Tengo una parte en mi aplicación angular en la que he enlazado un controlador,
desde entonces obtuve el Argumento 'fn' no es una función Error, ¿alguien puede mirar mi código y explicar por qué obtuve ese Error?

Estaría muy agradecido :)

html-markup:

<section class="col-lg-12" data-ng-controller="MessageController">
  <fieldset>
    <legend>{{ 'MESSAGES' | translate }}</legend>
  </fieldset>
  <div class="margin-left-15">
    <ul class="list-style-button">
      <li data-ng-repeat="message in MSG">{{ message }}</li>
    </ul>
  </div>
</section>

controlador:

(function() {
  'use strict';

  var controllers = angular.module('portal.controllers');

  controllers.controller('MessageController', ['$scope', 'MessageService', '$rootScope', function MessageController($scope, MessageService, $rootScope) {
    $rootScope.MSG = MessageService.getMessages();

    $rootScope.$watch('MSG', function(newValue) {
      $scope.MSG = newValue;
    });
  }]);
}());

Servicio:

(function() {

  'use strict';

  var messageServices = angular.module('portal.services');

  messageServices.factory('MessageService', ['MessageData', 'localStorageService', 'UserService'], function(MessageData, localStorageService, UserService) {
    return new MessageService(MessageData, localStorageService, UserService);
  });

  function MessageService(MessageData, localStorageService, UserService) {
    this.messageData = MessageData;
    this.localStorageService = localStorageService;
    this.userService = UserService;
  }

  MessageService.prototype.getMessages = function() {
    var locale = this.userService.getUserinfoLocale();
    var messages = this.localStorageService.get(Constants.key_messages + locale);
    if (messages !== null && messages !== undefined) {
      return JSON.parse(messages);
    } else {
      return this.messageData.query({
        locale: locale
      }, $.proxy(function(data, locale) {
        this.save(Constants.key_messages + locale, JSON.stringify(data));
      }, this));
    }
  };

  MessageService.prototype.save = function(key, value) {
    this.localStorageService.add(key, value);
  };

}());

datos:

(function() {
  'use strict';

  var data = angular.module('portal.data');

  data.factory('MessageData', function($resource) {
    return $resource(Constants.url_messages, {}, {
      query: {
        method: 'GET',
        params: {
          locale: 'locale'
        },
        isArray: true
      }
    });
  });
}());

orden de archivos js en la cabeza html:

<script src="js/lib/jquery-1.10.js"></script>
<script src="js/lib/angular.js"></script>
<script src="js/lib/angular-resource.js"></script>
<script src="js/lib/angular-translate.js"></script>
<script src="js/lib/angular-localstorage.js"></script>
<script src="js/lib/jquery-cookies.js"></script>
<script src="js/lib/bootstrap.js"></script>
<script src="js/portal.js"></script>