title: adding another module dependency in angularjs, the application stops working
body: <p>
  I ran into a weird problem that I could not figure out, I could not get a good explanation even after searching on the internet.
  </p>
  <p>
  I have a application (webpage) which consists of ui-bootstrap's accrodion element which gets the data from a json file by $http request. This part is working perfectly fine. Now I wanted to add a multiselect dropdown and I wanted to use the element provided in ui-select. But when I add the dependencies 'ngSanitize' and 'ui-select' in the module, the application doesn't work. I haven't added any dropdown elements, just the dependencies. I don't understand where the problem is.
  </p>
  <p>
  The original application controller
  </p>
  <pre><code>var app = angular.module('callApp', ['ui.bootstrap']);
  app.controller('firstController', function($scope, $http, $modal, $log) {
      //some functions are defined here
  });
  angular.module('callApp').service('popupService', function () {
      //service is defined
  });
  </code></pre>
  <p>
  Then i added the dependencies ngSanitize and ui.select
  </p>
  <pre><code>var app = angular.module('callApp', ['ui.bootstrap', 'ngSanitize', 'ui.select']);
  app.controller('firstController', function($scope, $http, $modal, $log) {
      //some functions are defined here
  });
  angular.module('callApp').service('popupService', function () {
      //service is defined
  });
  </code></pre>
  <p>
  Now the application doesn't work. I haven't modified any other function or added any elements in the html. Why does such a problem arrive? Is there anything wrong with the declaration?
  </p>