Merge commit godotengine/godot@c6c464cf9ae56e8b68620af65125dd980d0e8122

24 files changed, 128 insertions, 128 deletions

diff --git a/core/io/dir_access.cpp b/core/io/dir_access.cpp
index 7d76156309..18df616332 100644
--- a/core/io/dir_access.cpp
+++ b/core/io/dir_access.cpp
@@ -179,7 +179,7 @@ Error DirAccess::make_dir_recursive(const String &p_dir) {
 		curpath = curpath.path_join(subdirs[i]);
 		Error err = make_dir(curpath);
 		if (err != OK && err != ERR_ALREADY_EXISTS) {
-			ERR_FAIL_V_MSG(err, "Could not create directory: " + curpath);
+			ERR_FAIL_V_MSG(err, vformat("Could not create directory: '%s'.", curpath));
 		}
 	}
 
@@ -241,7 +241,7 @@ Ref<DirAccess> DirAccess::create_for_path(const String &p_path) {
 
 Ref<DirAccess> DirAccess::open(const String &p_path, Error *r_error) {
 	Ref<DirAccess> da = create_for_path(p_path);
-	ERR_FAIL_COND_V_MSG(da.is_null(), nullptr, "Cannot create DirAccess for path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(da.is_null(), nullptr, vformat("Cannot create DirAccess for path '%s'.", p_path));
 	Error err = da->change_dir(p_path);
 	if (r_error) {
 		*r_error = err;
@@ -347,10 +347,10 @@ Error DirAccess::copy(const String &p_from, const String &p_to, int p_chmod_flag
 	Error err;
 	{
 		Ref<FileAccess> fsrc = FileAccess::open(p_from, FileAccess::READ, &err);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Failed to open " + p_from);
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Failed to open '%s'.", p_from));
 
 		Ref<FileAccess> fdst = FileAccess::open(p_to, FileAccess::WRITE, &err);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Failed to open " + p_to);
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Failed to open '%s'.", p_to));
 
 		const size_t copy_buffer_limit = 65536; // 64 KB
 
@@ -446,11 +446,11 @@ Error DirAccess::_copy_dir(Ref<DirAccess> &p_target_da, const String &p_to, int
 		String target_dir = p_to + rel_path;
 		if (!p_target_da->dir_exists(target_dir)) {
 			Error err = p_target_da->make_dir(target_dir);
-			ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create directory '" + target_dir + "'.");
+			ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create directory '%s'.", target_dir));
 		}
 
 		Error err = change_dir(rel_path);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot change current directory to '" + rel_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot change current directory to '%s'.", rel_path));
 
 		err = _copy_dir(p_target_da, p_to + rel_path + "/", p_chmod_flags, p_copy_links);
 		if (err) {
@@ -468,11 +468,11 @@ Error DirAccess::copy_dir(const String &p_from, String p_to, int p_chmod_flags,
 	ERR_FAIL_COND_V_MSG(!dir_exists(p_from), ERR_FILE_NOT_FOUND, "Source directory doesn't exist.");
 
 	Ref<DirAccess> target_da = DirAccess::create_for_path(p_to);
-	ERR_FAIL_COND_V_MSG(target_da.is_null(), ERR_CANT_CREATE, "Cannot create DirAccess for path '" + p_to + "'.");
+	ERR_FAIL_COND_V_MSG(target_da.is_null(), ERR_CANT_CREATE, vformat("Cannot create DirAccess for path '%s'.", p_to));
 
 	if (!target_da->dir_exists(p_to)) {
 		Error err = target_da->make_dir_recursive(p_to);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create directory '" + p_to + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create directory '%s'.", p_to));
 	}
 
 	if (!p_to.ends_with("/")) {
diff --git a/core/io/dir_access.h b/core/io/dir_access.h
index 2567764e55..670c512ea9 100644
--- a/core/io/dir_access.h
+++ b/core/io/dir_access.h
@@ -118,10 +118,10 @@ public:
 		Ref<DirAccess> da = create(ACCESS_FILESYSTEM);
 		if (da->file_exists(p_path)) {
 			if (da->remove(p_path) != OK) {
-				ERR_FAIL_MSG("Cannot remove file or directory: " + p_path);
+				ERR_FAIL_MSG(vformat("Cannot remove file or directory: '%s'.", p_path));
 			}
 		} else {
-			ERR_FAIL_MSG("Cannot remove non-existent file or directory: " + p_path);
+			ERR_FAIL_MSG(vformat("Cannot remove non-existent file or directory: '%s'.", p_path));
 		}
 	}
 
diff --git a/core/io/file_access.cpp b/core/io/file_access.cpp
index 69ad8bbeda..e10462adcd 100644
--- a/core/io/file_access.cpp
+++ b/core/io/file_access.cpp
@@ -461,7 +461,7 @@ Vector<uint8_t> FileAccess::get_buffer(int64_t p_length) const {
 	}
 
 	Error err = data.resize(p_length);
-	ERR_FAIL_COND_V_MSG(err != OK, data, "Can't resize data to " + itos(p_length) + " elements.");
+	ERR_FAIL_COND_V_MSG(err != OK, data, vformat("Can't resize data to %d elements.", p_length));
 
 	uint8_t *w = data.ptrw();
 	int64_t len = get_buffer(w, p_length);
@@ -542,7 +542,7 @@ uint64_t FileAccess::get_modified_time(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	uint64_t mt = fa->_get_modified_time(p_file);
 	return mt;
@@ -554,7 +554,7 @@ BitField<FileAccess::UnixPermissionFlags> FileAccess::get_unix_permissions(const
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), 0, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_unix_permissions(p_file);
 }
@@ -565,7 +565,7 @@ Error FileAccess::set_unix_permissions(const String &p_file, BitField<FileAccess
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_unix_permissions(p_file, p_permissions);
 	return err;
@@ -577,7 +577,7 @@ bool FileAccess::get_hidden_attribute(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), false, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), false, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_hidden_attribute(p_file);
 }
@@ -588,7 +588,7 @@ Error FileAccess::set_hidden_attribute(const String &p_file, bool p_hidden) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_hidden_attribute(p_file, p_hidden);
 	return err;
@@ -600,7 +600,7 @@ bool FileAccess::get_read_only_attribute(const String &p_file) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), false, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), false, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	return fa->_get_read_only_attribute(p_file);
 }
@@ -611,7 +611,7 @@ Error FileAccess::set_read_only_attribute(const String &p_file, bool p_ro) {
 	}
 
 	Ref<FileAccess> fa = create_for_path(p_file);
-	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, "Cannot create FileAccess for path '" + p_file + "'.");
+	ERR_FAIL_COND_V_MSG(fa.is_null(), ERR_CANT_CREATE, vformat("Cannot create FileAccess for path '%s'.", p_file));
 
 	Error err = fa->_set_read_only_attribute(p_file, p_ro);
 	return err;
@@ -699,7 +699,7 @@ Vector<uint8_t> FileAccess::get_file_as_bytes(const String &p_path, Error *r_err
 		if (r_error) { // if error requested, do not throw error
 			return Vector<uint8_t>();
 		}
-		ERR_FAIL_V_MSG(Vector<uint8_t>(), "Can't open file from path '" + String(p_path) + "'.");
+		ERR_FAIL_V_MSG(Vector<uint8_t>(), vformat("Can't open file from path '%s'.", String(p_path)));
 	}
 	Vector<uint8_t> data;
 	data.resize(f->get_length());
@@ -717,7 +717,7 @@ String FileAccess::get_file_as_string(const String &p_path, Error *r_error) {
 		if (r_error) {
 			return String();
 		}
-		ERR_FAIL_V_MSG(String(), "Can't get file as string from path '" + String(p_path) + "'.");
+		ERR_FAIL_V_MSG(String(), vformat("Can't get file as string from path '%s'.", String(p_path)));
 	}
 
 	String ret;
diff --git a/core/io/file_access_compressed.cpp b/core/io/file_access_compressed.cpp
index 05335df9e9..84137251ef 100644
--- a/core/io/file_access_compressed.cpp
+++ b/core/io/file_access_compressed.cpp
@@ -60,7 +60,7 @@ Error FileAccessCompressed::open_after_magic(Ref<FileAccess> p_base) {
 	block_size = f->get_32();
 	if (block_size == 0) {
 		f.unref();
-		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, "Can't open compressed file '" + p_base->get_path() + "' with block size 0, it is corrupted.");
+		ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("Can't open compressed file '%s' with block size 0, it is corrupted.", p_base->get_path()));
 	}
 	read_total = f->get_32();
 	uint32_t bc = (read_total / block_size) + 1;
diff --git a/core/io/file_access_encrypted.cpp b/core/io/file_access_encrypted.cpp
index 6c406afff0..a84aa4c800 100644
--- a/core/io/file_access_encrypted.cpp
+++ b/core/io/file_access_encrypted.cpp
@@ -39,7 +39,7 @@
 #include <stdio.h>
 
 Error FileAccessEncrypted::open_and_parse(Ref<FileAccess> p_base, const Vector<uint8_t> &p_key, Mode p_mode, bool p_with_magic) {
-	ERR_FAIL_COND_V_MSG(file.is_valid(), ERR_ALREADY_IN_USE, "Can't open file while another file from path '" + file->get_path_absolute() + "' is open.");
+	ERR_FAIL_COND_V_MSG(file.is_valid(), ERR_ALREADY_IN_USE, vformat("Can't open file while another file from path '%s' is open.", file->get_path_absolute()));
 	ERR_FAIL_COND_V(p_key.size() != 32, ERR_INVALID_PARAMETER);
 
 	pos = 0;
diff --git a/core/io/file_access_memory.cpp b/core/io/file_access_memory.cpp
index 199a51e86d..2ead49ba81 100644
--- a/core/io/file_access_memory.cpp
+++ b/core/io/file_access_memory.cpp
@@ -87,7 +87,7 @@ Error FileAccessMemory::open_internal(const String &p_path, int p_mode_flags) {
 	//name = DirAccess::normalize_path(name);
 
 	HashMap<String, Vector<uint8_t>>::Iterator E = files->find(name);
-	ERR_FAIL_COND_V_MSG(!E, ERR_FILE_NOT_FOUND, "Can't find file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(!E, ERR_FILE_NOT_FOUND, vformat("Can't find file '%s'.", p_path));
 
 	data = E->value.ptrw();
 	length = E->value.size();
diff --git a/core/io/file_access_pack.cpp b/core/io/file_access_pack.cpp
index 6f2685163e..7bc96c4644 100644
--- a/core/io/file_access_pack.cpp
+++ b/core/io/file_access_pack.cpp
@@ -225,8 +225,8 @@ bool PackedSourcePCK::try_open_pack(const String &p_path, bool p_replace_files,
 	uint32_t ver_minor = f->get_32();
 	f->get_32(); // patch number, not used for validation.
 
-	ERR_FAIL_COND_V_MSG(version != PACK_FORMAT_VERSION, false, "Pack version unsupported: " + itos(version) + ".");
-	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, "Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
+	ERR_FAIL_COND_V_MSG(version != PACK_FORMAT_VERSION, false, vformat("Pack version unsupported: %d.", version));
+	ERR_FAIL_COND_V_MSG(ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR), false, vformat("Pack created with a newer version of the engine: %d.%d.", ver_major, ver_minor));
 
 	uint32_t pack_flags = f->get_32();
 	uint64_t file_base = f->get_64();
@@ -388,7 +388,7 @@ void FileAccessPack::close() {
 FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFile &p_file) :
 		pf(p_file),
 		f(FileAccess::open(pf.pack, FileAccess::READ)) {
-	ERR_FAIL_COND_MSG(f.is_null(), "Can't open pack-referenced file '" + String(pf.pack) + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Can't open pack-referenced file '%s'.", String(pf.pack)));
 
 	f->seek(pf.offset);
 	off = pf.offset;
@@ -396,7 +396,7 @@ FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFil
 	if (pf.encrypted) {
 		Ref<FileAccessEncrypted> fae;
 		fae.instantiate();
-		ERR_FAIL_COND_MSG(fae.is_null(), "Can't open encrypted pack-referenced file '" + String(pf.pack) + "'.");
+		ERR_FAIL_COND_MSG(fae.is_null(), vformat("Can't open encrypted pack-referenced file '%s'.", String(pf.pack)));
 
 		Vector<uint8_t> key;
 		key.resize(32);
@@ -405,7 +405,7 @@ FileAccessPack::FileAccessPack(const String &p_path, const PackedData::PackedFil
 		}
 
 		Error err = fae->open_and_parse(f, key, FileAccessEncrypted::MODE_READ, false);
-		ERR_FAIL_COND_MSG(err, "Can't open encrypted pack-referenced file '" + String(pf.pack) + "'.");
+		ERR_FAIL_COND_MSG(err, vformat("Can't open encrypted pack-referenced file '%s'.", String(pf.pack)));
 		f = fae;
 		off = 0;
 	}
diff --git a/core/io/file_access_zip.cpp b/core/io/file_access_zip.cpp
index 38f86bd04d..71ce18145a 100644
--- a/core/io/file_access_zip.cpp
+++ b/core/io/file_access_zip.cpp
@@ -118,7 +118,7 @@ void ZipArchive::close_handle(unzFile p_file) const {
 }
 
 unzFile ZipArchive::get_file_handle(const String &p_file) const {
-	ERR_FAIL_COND_V_MSG(!file_exists(p_file), nullptr, "File '" + p_file + " doesn't exist.");
+	ERR_FAIL_COND_V_MSG(!file_exists(p_file), nullptr, vformat("File '%s' doesn't exist.", p_file));
 	File file = files[p_file];
 
 	zlib_filefunc_def io;
@@ -138,7 +138,7 @@ unzFile ZipArchive::get_file_handle(const String &p_file) const {
 	io.free_mem = godot_free;
 
 	unzFile pkg = unzOpen2(packages[file.package].filename.utf8().get_data(), &io);
-	ERR_FAIL_NULL_V_MSG(pkg, nullptr, "Cannot open file '" + packages[file.package].filename + "'.");
+	ERR_FAIL_NULL_V_MSG(pkg, nullptr, vformat("Cannot open file '%s'.", packages[file.package].filename));
 	int unz_err = unzGoToFilePos(pkg, &file.file_pos);
 	if (unz_err != UNZ_OK || unzOpenCurrentFile(pkg) != UNZ_OK) {
 		unzClose(pkg);
diff --git a/core/io/http_client.cpp b/core/io/http_client.cpp
index 323990ef7e..9d2adb2fcf 100644
--- a/core/io/http_client.cpp
+++ b/core/io/http_client.cpp
@@ -102,9 +102,9 @@ String HTTPClient::query_string_from_dict(const Dictionary &p_dict) {
 Error HTTPClient::verify_headers(const Vector<String> &p_headers) {
 	for (int i = 0; i < p_headers.size(); i++) {
 		String sanitized = p_headers[i].strip_edges();
-		ERR_FAIL_COND_V_MSG(sanitized.is_empty(), ERR_INVALID_PARAMETER, "Invalid HTTP header at index " + itos(i) + ": empty.");
+		ERR_FAIL_COND_V_MSG(sanitized.is_empty(), ERR_INVALID_PARAMETER, vformat("Invalid HTTP header at index %d: empty.", i));
 		ERR_FAIL_COND_V_MSG(sanitized.find(":") < 1, ERR_INVALID_PARAMETER,
-				"Invalid HTTP header at index " + itos(i) + ": String must contain header-value pair, delimited by ':', but was: " + p_headers[i]);
+				vformat("Invalid HTTP header at index %d: String must contain header-value pair, delimited by ':', but was: '%s'.", i, p_headers[i]));
 	}
 
 	return OK;
diff --git a/core/io/image.cpp b/core/io/image.cpp
index 40f1499f77..613e740dd6 100644
--- a/core/io/image.cpp
+++ b/core/io/image.cpp
@@ -537,7 +537,7 @@ static bool _are_formats_compatible(Image::Format p_format0, Image::Format p_for
 }
 
 void Image::convert(Format p_new_format) {
-	ERR_FAIL_INDEX_MSG(p_new_format, FORMAT_MAX, "The Image format specified (" + itos(p_new_format) + ") is out of range. See Image's Format enum.");
+	ERR_FAIL_INDEX_MSG(p_new_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_new_format));
 	if (data.size() == 0) {
 		return;
 	}
@@ -1134,9 +1134,9 @@ void Image::resize(int p_width, int p_height, Interpolation p_interpolation) {
 
 	ERR_FAIL_COND_MSG(p_width <= 0, "Image width must be greater than 0.");
 	ERR_FAIL_COND_MSG(p_height <= 0, "Image height must be greater than 0.");
-	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH, "Image width cannot be greater than " + itos(MAX_WIDTH) + ".");
-	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT, "Image height cannot be greater than " + itos(MAX_HEIGHT) + ".");
-	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS, "Too many pixels for image, maximum is " + itos(MAX_PIXELS));
+	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH, vformat("Image width cannot be greater than %d pixels.", MAX_WIDTH));
+	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT, vformat("Image height cannot be greater than %d pixels.", MAX_HEIGHT));
+	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS, vformat("Too many pixels for image, maximum is %d pixels.", MAX_PIXELS));
 
 	if (p_width == width && p_height == height) {
 		return;
@@ -1437,8 +1437,8 @@ void Image::crop_from_point(int p_x, int p_y, int p_width, int p_height) {
 	ERR_FAIL_COND_MSG(p_y < 0, "Start y position cannot be smaller than 0.");
 	ERR_FAIL_COND_MSG(p_width <= 0, "Width of image must be greater than 0.");
 	ERR_FAIL_COND_MSG(p_height <= 0, "Height of image must be greater than 0.");
-	ERR_FAIL_COND_MSG(p_x + p_width > MAX_WIDTH, "End x position cannot be greater than " + itos(MAX_WIDTH) + ".");
-	ERR_FAIL_COND_MSG(p_y + p_height > MAX_HEIGHT, "End y position cannot be greater than " + itos(MAX_HEIGHT) + ".");
+	ERR_FAIL_COND_MSG(p_x + p_width > MAX_WIDTH, vformat("End x position cannot be greater than %d.", MAX_WIDTH));
+	ERR_FAIL_COND_MSG(p_y + p_height > MAX_HEIGHT, vformat("End y position cannot be greater than %d.", MAX_HEIGHT));
 
 	/* to save memory, cropping should be done in-place, however, since this function
 	   will most likely either not be used much, or in critical areas, for now it won't, because
@@ -1486,8 +1486,8 @@ void Image::crop(int p_width, int p_height) {
 
 void Image::rotate_90(ClockDirection p_direction) {
 	ERR_FAIL_COND_MSG(!_can_modify(format), "Cannot rotate in compressed or custom image formats.");
-	ERR_FAIL_COND_MSG(width <= 0, "The Image width specified (" + itos(width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(height <= 0, "The Image height specified (" + itos(height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", width));
+	ERR_FAIL_COND_MSG(height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", height));
 
 	bool used_mipmaps = has_mipmaps();
 	if (used_mipmaps) {
@@ -1604,8 +1604,8 @@ void Image::rotate_90(ClockDirection p_direction) {
 
 void Image::rotate_180() {
 	ERR_FAIL_COND_MSG(!_can_modify(format), "Cannot rotate in compressed or custom image formats.");
-	ERR_FAIL_COND_MSG(width <= 0, "The Image width specified (" + itos(width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(height <= 0, "The Image height specified (" + itos(height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", width));
+	ERR_FAIL_COND_MSG(height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", height));
 
 	bool used_mipmaps = has_mipmaps();
 	if (used_mipmaps) {
@@ -2251,15 +2251,15 @@ void Image::set_data(int p_width, int p_height, bool p_use_mipmaps, Format p_for
 }
 
 void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format) {
-	ERR_FAIL_COND_MSG(p_width <= 0, "The Image width specified (" + itos(p_width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(p_height <= 0, "The Image height specified (" + itos(p_height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(p_width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", p_width));
+	ERR_FAIL_COND_MSG(p_height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", p_height));
 	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH,
-			"The Image width specified (" + itos(p_width) + " pixels) cannot be greater than " + itos(MAX_WIDTH) + "pixels.");
+			vformat("The Image width specified (%d pixels) cannot be greater than %d pixels.", p_width, MAX_WIDTH));
 	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT,
-			"The Image height specified (" + itos(p_height) + " pixels) cannot be greater than " + itos(MAX_HEIGHT) + "pixels.");
+			vformat("The Image height specified (%d pixels) cannot be greater than %d pixels.", p_height, MAX_HEIGHT));
 	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS,
-			"Too many pixels for Image. Maximum is " + itos(MAX_WIDTH) + "x" + itos(MAX_HEIGHT) + " = " + itos(MAX_PIXELS) + "pixels.");
-	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, "The Image format specified (" + itos(p_format) + ") is out of range. See Image's Format enum.");
+			vformat("Too many pixels for Image. Maximum is %dx%d = %d pixels.", MAX_WIDTH, MAX_HEIGHT, MAX_PIXELS));
+	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_format));
 
 	int mm = 0;
 	int64_t size = _get_dst_image_size(p_width, p_height, p_format, mm, p_use_mipmaps ? -1 : 0);
@@ -2277,15 +2277,15 @@ void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Forma
 }
 
 void Image::initialize_data(int p_width, int p_height, bool p_use_mipmaps, Format p_format, const Vector<uint8_t> &p_data) {
-	ERR_FAIL_COND_MSG(p_width <= 0, "The Image width specified (" + itos(p_width) + " pixels) must be greater than 0 pixels.");
-	ERR_FAIL_COND_MSG(p_height <= 0, "The Image height specified (" + itos(p_height) + " pixels) must be greater than 0 pixels.");
+	ERR_FAIL_COND_MSG(p_width <= 0, vformat("The Image width specified (%d pixels) must be greater than 0 pixels.", p_width));
+	ERR_FAIL_COND_MSG(p_height <= 0, vformat("The Image height specified (%d pixels) must be greater than 0 pixels.", p_height));
 	ERR_FAIL_COND_MSG(p_width > MAX_WIDTH,
-			"The Image width specified (" + itos(p_width) + " pixels) cannot be greater than " + itos(MAX_WIDTH) + " pixels.");
+			vformat("The Image width specified (%d pixels) cannot be greater than %d pixels.", p_width, MAX_WIDTH));
 	ERR_FAIL_COND_MSG(p_height > MAX_HEIGHT,
-			"The Image height specified (" + itos(p_height) + " pixels) cannot be greater than " + itos(MAX_HEIGHT) + " pixels.");
+			vformat("The Image height specified (%d pixels) cannot be greater than %d pixels.", p_height, MAX_HEIGHT));
 	ERR_FAIL_COND_MSG(p_width * p_height > MAX_PIXELS,
-			"Too many pixels for Image. Maximum is " + itos(MAX_WIDTH) + "x" + itos(MAX_HEIGHT) + " = " + itos(MAX_PIXELS) + "pixels .");
-	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, "The Image format specified (" + itos(p_format) + ") is out of range. See Image's Format enum.");
+			vformat("Too many pixels for Image. Maximum is %dx%d = %d pixels.", MAX_WIDTH, MAX_HEIGHT, MAX_PIXELS));
+	ERR_FAIL_INDEX_MSG(p_format, FORMAT_MAX, vformat("The Image format specified (%d) is out of range. See Image's Format enum.", p_format));
 
 	int mm;
 	int64_t size = _get_dst_image_size(p_width, p_height, p_format, mm, p_use_mipmaps ? -1 : 0);
@@ -2579,7 +2579,7 @@ Image::AlphaMode Image::detect_alpha() const {
 Error Image::load(const String &p_path) {
 #ifdef DEBUG_ENABLED
 	if (p_path.begins_with("res://") && ResourceLoader::exists(p_path)) {
-		WARN_PRINT("Loaded resource as image file, this will not work on export: '" + p_path + "'. Instead, import the image file as an Image resource and load it normally as a resource.");
+		WARN_PRINT(vformat("Loaded resource as image file, this will not work on export: '%s'. Instead, import the image file as an Image resource and load it normally as a resource.", p_path));
 	}
 #endif
 	return ImageLoader::load_image(p_path, this);
@@ -2588,7 +2588,7 @@ Error Image::load(const String &p_path) {
 Ref<Image> Image::load_from_file(const String &p_path) {
 #ifdef DEBUG_ENABLED
 	if (p_path.begins_with("res://") && ResourceLoader::exists(p_path)) {
-		WARN_PRINT("Loaded resource as image file, this will not work on export: '" + p_path + "'. Instead, import the image file as an Image resource and load it normally as a resource.");
+		WARN_PRINT(vformat("Loaded resource as image file, this will not work on export: '%s'. Instead, import the image file as an Image resource and load it normally as a resource.", p_path));
 	}
 #endif
 	Ref<Image> image;
@@ -2651,7 +2651,7 @@ Error Image::save_webp(const String &p_path, const bool p_lossy, const float p_q
 	if (save_webp_func == nullptr) {
 		return ERR_UNAVAILABLE;
 	}
-	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), ERR_INVALID_PARAMETER, "The WebP lossy quality was set to " + rtos(p_quality) + ", which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).");
+	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), ERR_INVALID_PARAMETER, vformat("The WebP lossy quality was set to %f, which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).", p_quality));
 
 	return save_webp_func(p_path, Ref<Image>((Image *)this), p_lossy, p_quality);
 }
@@ -2660,7 +2660,7 @@ Vector<uint8_t> Image::save_webp_to_buffer(const bool p_lossy, const float p_qua
 	if (save_webp_buffer_func == nullptr) {
 		return Vector<uint8_t>();
 	}
-	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), Vector<uint8_t>(), "The WebP lossy quality was set to " + rtos(p_quality) + ", which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).");
+	ERR_FAIL_COND_V_MSG(p_lossy && !(0.0f <= p_quality && p_quality <= 1.0f), Vector<uint8_t>(), vformat("The WebP lossy quality was set to %f, which is not valid. WebP lossy quality must be between 0.0 and 1.0 (inclusive).", p_quality));
 
 	return save_webp_buffer_func(Ref<Image>((Image *)this), p_lossy, p_quality);
 }
diff --git a/core/io/image_loader.cpp b/core/io/image_loader.cpp
index 5724cd66a9..8e87569d7c 100644
--- a/core/io/image_loader.cpp
+++ b/core/io/image_loader.cpp
@@ -89,7 +89,7 @@ Error ImageLoader::load_image(const String &p_file, Ref<Image> p_image, Ref<File
 	if (f.is_null()) {
 		Error err;
 		f = FileAccess::open(p_file, FileAccess::READ, &err);
-		ERR_FAIL_COND_V_MSG(f.is_null(), err, "Error opening file '" + p_file + "'.");
+		ERR_FAIL_COND_V_MSG(f.is_null(), err, vformat("Error opening file '%s'.", p_file));
 	}
 
 	String extension = p_file.get_extension();
@@ -100,7 +100,7 @@ Error ImageLoader::load_image(const String &p_file, Ref<Image> p_image, Ref<File
 		}
 		Error err = loader.write[i]->load_image(p_image, f, p_flags, p_scale);
 		if (err != OK) {
-			ERR_PRINT("Error loading image: " + p_file);
+			ERR_PRINT(vformat("Error loading image: '%s'.", p_file));
 		}
 
 		if (err != ERR_FILE_UNRECOGNIZED) {
diff --git a/core/io/ip.cpp b/core/io/ip.cpp
index cf152cb41a..381436dc7a 100644
--- a/core/io/ip.cpp
+++ b/core/io/ip.cpp
@@ -203,7 +203,7 @@ IPAddress IP::get_resolve_item_address(ResolverID p_id) const {
 	MutexLock lock(resolver->mutex);
 
 	if (resolver->queue[p_id].status.get() != IP::RESOLVER_STATUS_DONE) {
-		ERR_PRINT("Resolve of '" + resolver->queue[p_id].hostname + "'' didn't complete yet.");
+		ERR_PRINT(vformat("Resolve of '%s' didn't complete yet.", resolver->queue[p_id].hostname));
 		return IPAddress();
 	}
 
@@ -222,7 +222,7 @@ Array IP::get_resolve_item_addresses(ResolverID p_id) const {
 	MutexLock lock(resolver->mutex);
 
 	if (resolver->queue[p_id].status.get() != IP::RESOLVER_STATUS_DONE) {
-		ERR_PRINT("Resolve of '" + resolver->queue[p_id].hostname + "'' didn't complete yet.");
+		ERR_PRINT(vformat("Resolve of '%s' didn't complete yet.", resolver->queue[p_id].hostname));
 		return Array();
 	}
 
diff --git a/core/io/json.cpp b/core/io/json.cpp
index 0bbe79a0d1..989b292cbd 100644
--- a/core/io/json.cpp
+++ b/core/io/json.cpp
@@ -1404,7 +1404,7 @@ Error ResourceFormatSaverJSON::save(const Ref<Resource> &p_resource, const Strin
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_path, FileAccess::WRITE, &err);
 
-	ERR_FAIL_COND_V_MSG(err, err, "Cannot save json '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err, err, vformat("Cannot save json '%s'.", p_path));
 
 	file->store_string(source);
 	if (file->get_error() != OK && file->get_error() != ERR_FILE_EOF) {
diff --git a/core/io/marshalls.cpp b/core/io/marshalls.cpp
index 8d6334b4ab..d425af0afd 100644
--- a/core/io/marshalls.cpp
+++ b/core/io/marshalls.cpp
@@ -700,9 +700,9 @@ Error decode_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int
 						if (str == "script" && value.get_type() != Variant::NIL) {
 							ERR_FAIL_COND_V_MSG(value.get_type() != Variant::STRING, ERR_INVALID_DATA, "Invalid value for \"script\" property, expected script path as String.");
 							String path = value;
-							ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, "Invalid script path: '" + path + "'.");
+							ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, vformat("Invalid script path: '%s'.", path));
 							Ref<Script> script = ResourceLoader::load(path, "Script");
-							ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, "Can't load script at path: '" + path + "'.");
+							ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, vformat("Can't load script at path: '%s'.", path));
 							obj->set_script(script);
 						} else {
 							obj->set(str, value);
@@ -822,9 +822,9 @@ Error decode_variant(Variant &r_variant, const uint8_t *p_buffer, int p_len, int
 
 					builtin_type = Variant::OBJECT;
 					if (p_allow_objects) {
-						ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, "Invalid script path: '" + path + "'.");
+						ERR_FAIL_COND_V_MSG(path.is_empty() || !path.begins_with("res://") || !ResourceLoader::exists(path, "Script"), ERR_INVALID_DATA, vformat("Invalid script path: '%s'.", path));
 						script = ResourceLoader::load(path, "Script");
-						ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, "Can't load script at path: '" + path + "'.");
+						ERR_FAIL_COND_V_MSG(script.is_null(), ERR_INVALID_DATA, vformat("Can't load script at path: '%s'.", path));
 						class_name = script->get_instance_base_type();
 					} else {
 						class_name = EncodedObjectAsID::get_class_static();
diff --git a/core/io/pck_packer.cpp b/core/io/pck_packer.cpp
index 270f154887..9127d65abd 100644
--- a/core/io/pck_packer.cpp
+++ b/core/io/pck_packer.cpp
@@ -86,7 +86,7 @@ Error PCKPacker::pck_start(const String &p_pck_path, int p_alignment, const Stri
 	enc_dir = p_encrypt_directory;
 
 	file = FileAccess::open(p_pck_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(file.is_null(), ERR_CANT_CREATE, "Can't open file to write: " + String(p_pck_path) + ".");
+	ERR_FAIL_COND_V_MSG(file.is_null(), ERR_CANT_CREATE, vformat("Can't open file to write: '%s'.", String(p_pck_path)));
 
 	alignment = p_alignment;
 
diff --git a/core/io/plist.cpp b/core/io/plist.cpp
index de3ab52644..9fb0b461f1 100644
--- a/core/io/plist.cpp
+++ b/core/io/plist.cpp
@@ -452,7 +452,7 @@ PList::PList() {
 PList::PList(const String &p_string) {
 	String err_str;
 	bool ok = load_string(p_string, err_str);
-	ERR_FAIL_COND_MSG(!ok, "PList: " + err_str);
+	ERR_FAIL_COND_MSG(!ok, vformat("PList: %s.", err_str));
 }
 
 uint64_t PList::read_bplist_var_size_int(Ref<FileAccess> p_file, uint8_t p_size) {
diff --git a/core/io/remote_filesystem_client.cpp b/core/io/remote_filesystem_client.cpp
index ee44f19ec1..7985a59d43 100644
--- a/core/io/remote_filesystem_client.cpp
+++ b/core/io/remote_filesystem_client.cpp
@@ -98,7 +98,7 @@ Error RemoteFilesystemClient::_store_file(const String &p_path, const LocalVecto
 	}
 
 	Ref<FileAccess> f = FileAccess::open(full_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, "Unable to open file for writing to remote filesystem cache: " + p_path);
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, vformat("Unable to open file for writing to remote filesystem cache: '%s'.", p_path));
 	f->store_buffer(p_file.ptr(), p_file.size());
 	Error err = f->get_error();
 	if (err) {
@@ -117,10 +117,10 @@ Error RemoteFilesystemClient::_store_cache_file(const Vector<FileCache> &p_cache
 	String full_path = cache_path.path_join(FILES_CACHE_FILE);
 	String base_file_dir = full_path.get_base_dir();
 	Error err = DirAccess::make_dir_recursive_absolute(base_file_dir);
-	ERR_FAIL_COND_V_MSG(err != OK && err != ERR_ALREADY_EXISTS, err, "Unable to create base directory to store cache file: " + base_file_dir);
+	ERR_FAIL_COND_V_MSG(err != OK && err != ERR_ALREADY_EXISTS, err, vformat("Unable to create base directory to store cache file: '%s'.", base_file_dir));
 
 	Ref<FileAccess> f = FileAccess::open(full_path, FileAccess::WRITE);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, "Unable to open the remote cache file for writing: " + full_path);
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_FILE_CANT_OPEN, vformat("Unable to open the remote cache file for writing: '%s'.", full_path));
 	f->store_line(itos(FILESYSTEM_CACHE_VERSION));
 	for (int i = 0; i < p_cache.size(); i++) {
 		String l = p_cache[i].path + "::" + itos(p_cache[i].server_modified_time) + "::" + itos(p_cache[i].modified_time);
@@ -153,10 +153,10 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 	tcp_client.instantiate();
 
 	IPAddress ip = p_host.is_valid_ip_address() ? IPAddress(p_host) : IP::get_singleton()->resolve_hostname(p_host);
-	ERR_FAIL_COND_V_MSG(!ip.is_valid(), ERR_INVALID_PARAMETER, "Unable to resolve remote filesystem server hostname: " + p_host);
+	ERR_FAIL_COND_V_MSG(!ip.is_valid(), ERR_INVALID_PARAMETER, vformat("Unable to resolve remote filesystem server hostname: '%s'.", p_host));
 	print_verbose(vformat("Remote Filesystem: Connecting to host %s, port %d.", ip, p_port));
 	Error err = tcp_client->connect_to_host(ip, p_port);
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Unable to open connection to remote file server (" + String(p_host) + ", port " + itos(p_port) + ") failed.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Unable to open connection to remote file server (%s, port %d) failed.", String(p_host), p_port));
 
 	while (tcp_client->get_status() == StreamPeerTCP::STATUS_CONNECTING) {
 		tcp_client->poll();
@@ -164,7 +164,7 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 	}
 
 	if (tcp_client->get_status() != StreamPeerTCP::STATUS_CONNECTED) {
-		ERR_FAIL_V_MSG(ERR_CANT_CONNECT, "Connection to remote file server (" + String(p_host) + ", port " + itos(p_port) + ") failed.");
+		ERR_FAIL_V_MSG(ERR_CANT_CONNECT, vformat("Connection to remote file server (%s, port %d) failed.", String(p_host), p_port));
 	}
 
 	// Connection OK, now send the current file state.
@@ -283,7 +283,7 @@ Error RemoteFilesystemClient::_synchronize_with_server(const String &p_host, int
 
 		err = tcp_client->get_data(file_buffer.ptr(), file_size);
 		if (err != OK) {
-			ERR_PRINT("Error retrieving file from remote filesystem: " + file);
+			ERR_PRINT(vformat("Error retrieving file from remote filesystem: '%s'.", file));
 			server_disconnected = true;
 		}
 
diff --git a/core/io/resource.cpp b/core/io/resource.cpp
index 1f2ebbbd50..5b2af556fe 100644
--- a/core/io/resource.cpp
+++ b/core/io/resource.cpp
@@ -78,7 +78,7 @@ void Resource::set_path(const String &p_path, bool p_take_over) {
 				existing->path_cache = String();
 				ResourceCache::resources.erase(p_path);
 			} else {
-				ERR_FAIL_MSG("Another resource is loaded from path '" + p_path + "' (possible cyclic resource inclusion).");
+				ERR_FAIL_MSG(vformat("Another resource is loaded from path '%s' (possible cyclic resource inclusion).", p_path));
 			}
 		}
 
diff --git a/core/io/resource_format_binary.cpp b/core/io/resource_format_binary.cpp
index 7d5b305eb0..a714a065b5 100644
--- a/core/io/resource_format_binary.cpp
+++ b/core/io/resource_format_binary.cpp
@@ -413,7 +413,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 
 					//always use internal cache for loading internal resources
 					if (!internal_index_cache.has(path)) {
-						WARN_PRINT(String("Couldn't load resource (no cache): " + path).utf8().get_data());
+						WARN_PRINT(vformat("Couldn't load resource (no cache): %s.", path));
 						r_v = Variant();
 					} else {
 						r_v = internal_index_cache[path];
@@ -437,7 +437,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 					Ref<Resource> res = ResourceLoader::load(path, exttype, cache_mode_for_external);
 
 					if (res.is_null()) {
-						WARN_PRINT(String("Couldn't load resource: " + path).utf8().get_data());
+						WARN_PRINT(vformat("Couldn't load resource: %s.", path));
 					}
 					r_v = res;
 
@@ -460,7 +460,7 @@ Error ResourceLoaderBinary::parse_variant(Variant &r_v) {
 										ResourceLoader::notify_dependency_error(local_path, external_resources[erindex].path, external_resources[erindex].type);
 									} else {
 										error = ERR_FILE_MISSING_DEPENDENCIES;
-										ERR_FAIL_V_MSG(error, "Can't load dependency: " + external_resources[erindex].path + ".");
+										ERR_FAIL_V_MSG(error, vformat("Can't load dependency: '%s'.", external_resources[erindex].path));
 									}
 								}
 							} else {
@@ -706,7 +706,7 @@ Error ResourceLoaderBinary::load() {
 				ResourceLoader::notify_dependency_error(local_path, path, external_resources[i].type);
 			} else {
 				error = ERR_FILE_MISSING_DEPENDENCIES;
-				ERR_FAIL_V_MSG(error, "Can't load dependency: " + path + ".");
+				ERR_FAIL_V_MSG(error, vformat("Can't load dependency: '%s'.", path));
 			}
 		}
 	}
@@ -782,7 +782,7 @@ Error ResourceLoaderBinary::load() {
 						obj = missing_resource;
 					} else {
 						error = ERR_FILE_CORRUPT;
-						ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource of unrecognized type in file: " + t + ".");
+						ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("'%s': Resource of unrecognized type in file: '%s'.", local_path, t));
 					}
 				}
 
@@ -791,7 +791,7 @@ Error ResourceLoaderBinary::load() {
 					String obj_class = obj->get_class();
 					error = ERR_FILE_CORRUPT;
 					memdelete(obj); //bye
-					ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, local_path + ":Resource type in resource field not a resource, type is: " + obj_class + ".");
+					ERR_FAIL_V_MSG(ERR_FILE_CORRUPT, vformat("'%s': Resource type in resource field not a resource, type is: %s.", local_path, obj_class));
 				}
 
 				res = Ref<Resource>(r);
@@ -1001,7 +1001,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 		error = fac->open_after_magic(f);
 		if (error != OK) {
 			f.unref();
-			ERR_FAIL_MSG("Failed to open binary resource file: " + local_path + ".");
+			ERR_FAIL_MSG(vformat("Failed to open binary resource file: '%s'.", local_path));
 		}
 		f = fac;
 
@@ -1009,7 +1009,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 		// Not normal.
 		error = ERR_FILE_UNRECOGNIZED;
 		f.unref();
-		ERR_FAIL_MSG("Unrecognized binary resource file: " + local_path + ".");
+		ERR_FAIL_MSG(vformat("Unrecognized binary resource file: '%s'.", local_path));
 	}
 
 	bool big_endian = f->get_32();
@@ -1095,10 +1095,10 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 #ifdef TOOLS_ENABLED
 					// Silence a warning that can happen during the initial filesystem scan due to cache being regenerated.
 					if (ResourceLoader::get_resource_uid(res_path) != er.uid) {
-						WARN_PRINT(String(res_path + ": In external resource #" + itos(i) + ", invalid UID: " + ResourceUID::get_singleton()->id_to_text(er.uid) + " - using text path instead: " + er.path).utf8().get_data());
+						WARN_PRINT(vformat("'%s': In external resource #%d, invalid UID: '%s' - using text path instead: '%s'.", res_path, i, ResourceUID::get_singleton()->id_to_text(er.uid), er.path));
 					}
 #else
-					WARN_PRINT(String(res_path + ": In external resource #" + itos(i) + ", invalid UID: " + ResourceUID::get_singleton()->id_to_text(er.uid) + " - using text path instead: " + er.path).utf8().get_data());
+					WARN_PRINT(vformat("'%s': In external resource #%d, invalid UID: '%s' - using text path instead: '%s'.", res_path, i, ResourceUID::get_singleton()->id_to_text(er.uid), er.path));
 #endif
 				}
 			}
@@ -1122,7 +1122,7 @@ void ResourceLoaderBinary::open(Ref<FileAccess> p_f, bool p_no_resources, bool p
 	if (f->eof_reached()) {
 		error = ERR_FILE_CORRUPT;
 		f.unref();
-		ERR_FAIL_MSG("Premature end of file (EOF): " + local_path + ".");
+		ERR_FAIL_MSG(vformat("Premature end of file (EOF): '%s'.", local_path));
 	}
 }
 
@@ -1226,7 +1226,7 @@ Ref<Resource> ResourceFormatLoaderBinary::load(const String &p_path, const Strin
 	Error err;
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, Ref<Resource>(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, Ref<Resource>(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	switch (p_cache_mode) {
@@ -1303,7 +1303,7 @@ bool ResourceFormatLoaderBinary::handles_type(const String &p_type) const {
 
 void ResourceFormatLoaderBinary::get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_MSG(f.is_null(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -1313,7 +1313,7 @@ void ResourceFormatLoaderBinary::get_dependencies(const String &p_path, List<Str
 
 Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, const HashMap<String, String> &p_map) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 	Ref<FileAccess> fw;
 
@@ -1326,23 +1326,23 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 		Ref<FileAccessCompressed> fac;
 		fac.instantiate();
 		Error err = fac->open_after_magic(f);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 		f = fac;
 
 		Ref<FileAccessCompressed> facw;
 		facw.instantiate();
 		facw->configure("RSCC");
 		err = facw->open_internal(p_path + ".depren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, "Cannot create file '" + p_path + ".depren'.");
+		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, vformat("Cannot create file '%s.depren'.", p_path));
 
 		fw = facw;
 
 	} else if (header[0] != 'R' || header[1] != 'S' || header[2] != 'R' || header[3] != 'C') {
 		// Not normal.
-		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, "Unrecognized binary resource file '" + local_path + "'.");
+		ERR_FAIL_V_MSG(ERR_FILE_UNRECOGNIZED, vformat("Unrecognized binary resource file '%s'.", local_path));
 	} else {
 		fw = FileAccess::open(p_path + ".depren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, "Cannot create file '" + p_path + ".depren'.");
+		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, vformat("Cannot create file '%s.depren'.", p_path));
 
 		uint8_t magic[4] = { 'R', 'S', 'R', 'C' };
 		fw->store_buffer(magic, 4);
@@ -1374,12 +1374,12 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 		// Use the old approach.
 
-		WARN_PRINT("This file is old, so it can't refactor dependencies, opening and resaving '" + p_path + "'.");
+		WARN_PRINT(vformat("This file is old, so it can't refactor dependencies, opening and resaving '%s'.", p_path));
 
 		Error err;
 		f = FileAccess::open(p_path, FileAccess::READ, &err);
 
-		ERR_FAIL_COND_V_MSG(err != OK, ERR_FILE_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, ERR_FILE_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 		ResourceLoaderBinary loader;
 		loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -1525,7 +1525,7 @@ Error ResourceFormatLoaderBinary::rename_dependencies(const String &p_path, cons
 
 void ResourceFormatLoaderBinary::get_classes_used(const String &p_path, HashSet<StringName> *r_classes) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_MSG(f.is_null(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_MSG(f.is_null(), vformat("Cannot open file '%s'.", p_path));
 
 	ResourceLoaderBinary loader;
 	loader.local_path = ProjectSettings::get_singleton()->localize_path(p_path);
@@ -2029,7 +2029,7 @@ void ResourceFormatSaverBinaryInstance::_find_resources(const Variant &p_variant
 
 			if (!p_main && (!bundle_resources) && !res->is_built_in()) {
 				if (res->get_path() == path) {
-					ERR_PRINT("Circular reference to resource being saved found: '" + local_path + "' will be null next time it's loaded.");
+					ERR_PRINT(vformat("Circular reference to resource being saved found: '%s' will be null next time it's loaded.", local_path));
 					return;
 				}
 				int idx = external_resources.size();
@@ -2155,7 +2155,7 @@ Error ResourceFormatSaverBinaryInstance::save(const String &p_path, const Ref<Re
 		f = FileAccess::open(p_path, FileAccess::WRITE, &err);
 	}
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot create file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot create file '%s'.", p_path));
 
 	relative_paths = p_flags & ResourceSaver::FLAG_RELATIVE_PATHS;
 	skip_editor = p_flags & ResourceSaver::FLAG_OMIT_EDITOR_PROPERTIES;
@@ -2386,7 +2386,7 @@ Error ResourceFormatSaverBinaryInstance::save(const String &p_path, const Ref<Re
 
 Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceUID::ID p_uid) {
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), ERR_CANT_OPEN, vformat("Cannot open file '%s'.", p_path));
 
 	Ref<FileAccess> fw;
 
@@ -2399,14 +2399,14 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 		Ref<FileAccessCompressed> fac;
 		fac.instantiate();
 		Error err = fac->open_after_magic(f);
-		ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+		ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 		f = fac;
 
 		Ref<FileAccessCompressed> facw;
 		facw.instantiate();
 		facw->configure("RSCC");
 		err = facw->open_internal(p_path + ".uidren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, "Cannot create file '" + p_path + ".uidren'.");
+		ERR_FAIL_COND_V_MSG(err, ERR_FILE_CORRUPT, vformat("Cannot create file '%s.uidren'.", p_path));
 
 		fw = facw;
 
@@ -2415,7 +2415,7 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 		return ERR_FILE_UNRECOGNIZED;
 	} else {
 		fw = FileAccess::open(p_path + ".uidren", FileAccess::WRITE);
-		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, "Cannot create file '" + p_path + ".uidren'.");
+		ERR_FAIL_COND_V_MSG(fw.is_null(), ERR_CANT_CREATE, vformat("Cannot create file '%s.uidren'.", p_path));
 
 		uint8_t magich[4] = { 'R', 'S', 'R', 'C' };
 		fw->store_buffer(magich, 4);
@@ -2446,7 +2446,7 @@ Error ResourceFormatSaverBinaryInstance::set_uid(const String &p_path, ResourceU
 
 		// Use the old approach.
 
-		WARN_PRINT("This file is old, so it does not support UIDs, opening and resaving '" + p_path + "'.");
+		WARN_PRINT(vformat("This file is old, so it does not support UIDs, opening and resaving '%s'.", p_path));
 		return ERR_UNAVAILABLE;
 	}
 
diff --git a/core/io/resource_importer.cpp b/core/io/resource_importer.cpp
index 1e481d3aaa..b72b19ae59 100644
--- a/core/io/resource_importer.cpp
+++ b/core/io/resource_importer.cpp
@@ -77,7 +77,7 @@ Error ResourceFormatImporter::_get_path_and_type(const String &p_path, PathAndTy
 		if (err == ERR_FILE_EOF) {
 			return OK;
 		} else if (err != OK) {
-			ERR_PRINT("ResourceFormatImporter::load - " + p_path + ".import:" + itos(lines) + " error: " + error_text);
+			ERR_PRINT(vformat("ResourceFormatImporter::load - %s.import:%d error: %s.", p_path, lines, error_text));
 			return err;
 		}
 
@@ -337,7 +337,7 @@ void ResourceFormatImporter::get_internal_resource_path_list(const String &p_pat
 		if (err == ERR_FILE_EOF) {
 			return;
 		} else if (err != OK) {
-			ERR_PRINT("ResourceFormatImporter::get_internal_resource_path_list - " + p_path + ".import:" + itos(lines) + " error: " + error_text);
+			ERR_PRINT(vformat("ResourceFormatImporter::get_internal_resource_path_list - %s.import:%d error: %s.", p_path, lines, error_text));
 			return;
 		}
 
diff --git a/core/io/resource_loader.cpp b/core/io/resource_loader.cpp
index df12a0a3fd..97e6f6da06 100644
--- a/core/io/resource_loader.cpp
+++ b/core/io/resource_loader.cpp
@@ -164,7 +164,7 @@ Ref<Resource> ResourceFormatLoader::load(const String &p_path, const String &p_o
 		}
 	}
 
-	ERR_FAIL_V_MSG(Ref<Resource>(), "Failed to load resource '" + p_path + "'. ResourceFormatLoader::load was not implemented for this resource type.");
+	ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Failed to load resource '%s'. ResourceFormatLoader::load was not implemented for this resource type.", p_path));
 }
 
 void ResourceFormatLoader::get_dependencies(const String &p_path, List<String> *p_dependencies, bool p_add_types) {
@@ -1165,7 +1165,7 @@ String ResourceLoader::_path_remap(const String &p_path, bool *r_translation_rem
 		// An extra remap may still be necessary afterwards due to the text -> binary converter on export.
 
 		String locale = TranslationServer::get_singleton()->get_locale();
-		ERR_FAIL_COND_V_MSG(locale.length() < 2, p_path, "Could not remap path '" + p_path + "' for translation as configured locale '" + locale + "' is invalid.");
+		ERR_FAIL_COND_V_MSG(locale.length() < 2, p_path, vformat("Could not remap path '%s' for translation as configured locale '%s' is invalid.", p_path, locale));
 
 		Vector<String> &res_remaps = *translation_remaps.getptr(new_path);
 
@@ -1224,7 +1224,7 @@ String ResourceLoader::_path_remap(const String &p_path, bool *r_translation_rem
 					if (err == ERR_FILE_EOF) {
 						break;
 					} else if (err != OK) {
-						ERR_PRINT("Parse error: " + p_path + ".remap:" + itos(lines) + " error: " + error_text + ".");
+						ERR_PRINT(vformat("Parse error: %s.remap:%d error: %s.", p_path, lines, error_text));
 						break;
 					}
 
diff --git a/core/io/resource_saver.cpp b/core/io/resource_saver.cpp
index d6f00719f8..b0c551abd2 100644
--- a/core/io/resource_saver.cpp
+++ b/core/io/resource_saver.cpp
@@ -100,7 +100,7 @@ void ResourceFormatSaver::_bind_methods() {
 }
 
 Error ResourceSaver::save(const Ref<Resource> &p_resource, const String &p_path, uint32_t p_flags) {
-	ERR_FAIL_COND_V_MSG(p_resource.is_null(), ERR_INVALID_PARAMETER, "Can't save empty resource to path '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(p_resource.is_null(), ERR_INVALID_PARAMETER, vformat("Can't save empty resource to path '%s'.", p_path));
 	String path = p_path;
 	if (path.is_empty()) {
 		path = p_resource->get_path();
diff --git a/core/io/translation_loader_po.cpp b/core/io/translation_loader_po.cpp
index e7b2accf2b..54979a458c 100644
--- a/core/io/translation_loader_po.cpp
+++ b/core/io/translation_loader_po.cpp
@@ -171,14 +171,14 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			// If we reached last line and it's not a content line, break, otherwise let processing that last loop
 			if (is_eof && l.is_empty()) {
 				if (status == STATUS_READING_ID || status == STATUS_READING_CONTEXT || (status == STATUS_READING_PLURAL && plural_index != plural_forms - 1)) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "Unexpected EOF while reading PO file at: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Unexpected EOF while reading PO file at: %s:%d.", path, line));
 				} else {
 					break;
 				}
 			}
 
 			if (l.begins_with("msgctxt")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_STRING && status != STATUS_READING_PLURAL, Ref<Resource>(), "Unexpected 'msgctxt', was expecting 'msgid_plural' or 'msgstr' before 'msgctxt' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_STRING && status != STATUS_READING_PLURAL, Ref<Resource>(), vformat("Unexpected 'msgctxt', was expecting 'msgid_plural' or 'msgstr' before 'msgctxt' while parsing: %s:%d.", path, line));
 
 				// In PO file, "msgctxt" appears before "msgid". If we encounter a "msgctxt", we add what we have read
 				// and set "entered_context" to true to prevent adding twice.
@@ -186,7 +186,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 					if (status == STATUS_READING_STRING) {
 						translation->add_message(msg_id, msg_str, msg_context);
 					} else if (status == STATUS_READING_PLURAL) {
-						ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+						ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 						translation->add_plural_message(msg_id, msgs_plural, msg_context);
 					}
 				}
@@ -198,9 +198,9 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 
 			if (l.begins_with("msgid_plural")) {
 				if (plural_forms == 0) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "PO file uses 'msgid_plural' but 'Plural-Forms' is invalid or missing in header: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("PO file uses 'msgid_plural' but 'Plural-Forms' is invalid or missing in header: %s:%d.", path, line));
 				} else if (status != STATUS_READING_ID) {
-					ERR_FAIL_V_MSG(Ref<Resource>(), "Unexpected 'msgid_plural', was expecting 'msgid' before 'msgid_plural' while parsing: " + path + ":" + itos(line));
+					ERR_FAIL_V_MSG(Ref<Resource>(), vformat("Unexpected 'msgid_plural', was expecting 'msgid' before 'msgid_plural' while parsing: %s:%d.", path, line));
 				}
 				// We don't record the message in "msgid_plural" itself as tr_n(), TTRN(), RTRN() interfaces provide the plural string already.
 				// We just have to reset variables related to plurals for "msgstr[]" later on.
@@ -210,14 +210,14 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				msgs_plural.resize(plural_forms);
 				status = STATUS_READING_PLURAL;
 			} else if (l.begins_with("msgid")) {
-				ERR_FAIL_COND_V_MSG(status == STATUS_READING_ID, Ref<Resource>(), "Unexpected 'msgid', was expecting 'msgstr' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status == STATUS_READING_ID, Ref<Resource>(), vformat("Unexpected 'msgid', was expecting 'msgstr' while parsing: %s:%d.", path, line));
 
 				if (!msg_id.is_empty()) {
 					if (!skip_this && !entered_context) {
 						if (status == STATUS_READING_STRING) {
 							translation->add_message(msg_id, msg_str, msg_context);
 						} else if (status == STATUS_READING_PLURAL) {
-							ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+							ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 							translation->add_plural_message(msg_id, msgs_plural, msg_context);
 						}
 					}
@@ -246,11 +246,11 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			}
 
 			if (l.begins_with("msgstr[")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_PLURAL, Ref<Resource>(), "Unexpected 'msgstr[]', was expecting 'msgid_plural' before 'msgstr[]' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_PLURAL, Ref<Resource>(), vformat("Unexpected 'msgstr[]', was expecting 'msgid_plural' before 'msgstr[]' while parsing: %s:%d.", path, line));
 				plural_index++; // Increment to add to the next slot in vector msgs_plural.
 				l = l.substr(9, l.length()).strip_edges();
 			} else if (l.begins_with("msgstr")) {
-				ERR_FAIL_COND_V_MSG(status != STATUS_READING_ID, Ref<Resource>(), "Unexpected 'msgstr', was expecting 'msgid' before 'msgstr' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(status != STATUS_READING_ID, Ref<Resource>(), vformat("Unexpected 'msgstr', was expecting 'msgid' before 'msgstr' while parsing: %s:%d.", path, line));
 				l = l.substr(6, l.length()).strip_edges();
 				status = STATUS_READING_STRING;
 			}
@@ -263,7 +263,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				continue; // Nothing to read or comment.
 			}
 
-			ERR_FAIL_COND_V_MSG(!l.begins_with("\"") || status == STATUS_NONE, Ref<Resource>(), "Invalid line '" + l + "' while parsing: " + path + ":" + itos(line));
+			ERR_FAIL_COND_V_MSG(!l.begins_with("\"") || status == STATUS_NONE, Ref<Resource>(), vformat("Invalid line '%s' while parsing: %s:%d.", l, path, line));
 
 			l = l.substr(1, l.length());
 			// Find final quote, ignoring escaped ones (\").
@@ -285,7 +285,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 				escape_next = false;
 			}
 
-			ERR_FAIL_COND_V_MSG(end_pos == -1, Ref<Resource>(), "Expected '\"' at end of message while parsing: " + path + ":" + itos(line));
+			ERR_FAIL_COND_V_MSG(end_pos == -1, Ref<Resource>(), vformat("Expected '\"' at end of message while parsing: %s:%d.", path, line));
 
 			l = l.substr(0, end_pos);
 			l = l.c_unescape();
@@ -297,7 +297,7 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			} else if (status == STATUS_READING_CONTEXT) {
 				msg_context += l;
 			} else if (status == STATUS_READING_PLURAL && plural_index >= 0) {
-				ERR_FAIL_COND_V_MSG(plural_index >= plural_forms, Ref<Resource>(), "Unexpected plural form while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(plural_index >= plural_forms, Ref<Resource>(), vformat("Unexpected plural form while parsing: %s:%d.", path, line));
 				msgs_plural.write[plural_index] = msgs_plural[plural_index] + l;
 			}
 
@@ -315,13 +315,13 @@ Ref<Resource> TranslationLoaderPO::load_translation(Ref<FileAccess> f, Error *r_
 			}
 		} else if (status == STATUS_READING_PLURAL) {
 			if (!skip_this && !msg_id.is_empty()) {
-				ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+				ERR_FAIL_COND_V_MSG(plural_index != plural_forms - 1, Ref<Resource>(), vformat("Number of 'msgstr[]' doesn't match with number of plural forms: %s:%d.", path, line));
 				translation->add_plural_message(msg_id, msgs_plural, msg_context);
 			}
 		}
 	}
 
-	ERR_FAIL_COND_V_MSG(config.is_empty(), Ref<Resource>(), "No config found in file: " + path + ".");
+	ERR_FAIL_COND_V_MSG(config.is_empty(), Ref<Resource>(), vformat("No config found in file: '%s'.", path));
 
 	Vector<String> configs = config.split("\n");
 	for (int i = 0; i < configs.size(); i++) {
@@ -351,7 +351,7 @@ Ref<Resource> TranslationLoaderPO::load(const String &p_path, const String &p_or
 	}
 
 	Ref<FileAccess> f = FileAccess::open(p_path, FileAccess::READ);
-	ERR_FAIL_COND_V_MSG(f.is_null(), Ref<Resource>(), "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(f.is_null(), Ref<Resource>(), vformat("Cannot open file '%s'.", p_path));
 
 	return load_translation(f, r_error);
 }
diff --git a/core/io/xml_parser.cpp b/core/io/xml_parser.cpp
index 69cb8d9f64..8021aa303e 100644
--- a/core/io/xml_parser.cpp
+++ b/core/io/xml_parser.cpp
@@ -431,7 +431,7 @@ String XMLParser::get_named_attribute_value(const String &p_name) const {
 		}
 	}
 
-	ERR_FAIL_COND_V_MSG(idx < 0, "", "Attribute not found: " + p_name + ".");
+	ERR_FAIL_COND_V_MSG(idx < 0, "", vformat("Attribute not found: '%s'.", p_name));
 
 	return attributes[idx].value;
 }
@@ -495,7 +495,7 @@ Error XMLParser::open(const String &p_path) {
 	Error err;
 	Ref<FileAccess> file = FileAccess::open(p_path, FileAccess::READ, &err);
 
-	ERR_FAIL_COND_V_MSG(err != OK, err, "Cannot open file '" + p_path + "'.");
+	ERR_FAIL_COND_V_MSG(err != OK, err, vformat("Cannot open file '%s'.", p_path));
 
 	length = file->get_length();
 	ERR_FAIL_COND_V(length < 1, ERR_FILE_CORRUPT);