fixes #3314

src/plugins.js

@@ -364,6 +364,15 @@ var fs = require('fs'),
 			translator.addTranslation(language, filename, lang.file);
 		});
 
+		var fallbackPath;
+		for(var resource in Plugins.customLanguageFallbacks) {
+			fallbackPath = Plugins.customLanguageFallbacks[resource];
+			params.router.get('/language/:lang/' + resource + '.json', function(req, res, next) {
+				winston.verbose('[translator] No resource file found for ' + req.params.lang + '/' + resource + ', using provided fallback language file');
+				res.sendFile(fallbackPath);
+			});
+		}
+
 		callback(null);
 	}
 

src/plugins/load.js

@@ -159,7 +159,8 @@ module.exports = function(Plugins) {
 			return callback();
 		}
 
-		var pathToFolder = path.join(__dirname, '../../node_modules/', pluginData.id, pluginData.languages);
+		var pathToFolder = path.join(__dirname, '../../node_modules/', pluginData.id, pluginData.languages),
+			fallbackMap = {};
 
 		utils.walk(pathToFolder, function(err, languages) {
 			var arr = [];
@@ -183,13 +184,20 @@ module.exports = function(Plugins) {
 						route: pathToLang.replace(pathToFolder, '')
 					});
 
+					if (pluginData.defaultLang) {
+						fallbackMap[path.basename(pathToLang, '.json')] = path.join(pathToFolder, pluginData.defaultLang, path.basename(pathToLang));
+					}
+
 					next();
 				});
 			}, function(err) {
 				if (err) {
 					return callback(err);
 				}
+
 				Plugins.customLanguages = Plugins.customLanguages.concat(arr);
+				Plugins.customLanguageFallbacks = fallbackMap;
+
 				callback();
 			});
 		});