Issues with nested route navigation and non loading http-mock

Hello I have a router with this:

   goToMessagesView: function () {
      this.transitionToRoute("app/messages");
    }

Uncaught Error: Assertion Failed: The route app/messages was not found

my router:

  this.route('app', function () {
    this.resource('fo', {path: 'fo/fo_id'});
    this.resource('messages');

If I navigate to 'http://localhost:4200/app/messages' it works but doesn't load the model from my http-mock as is in the route app/messages:

export default Ember.Route.extend({
  model: function () {
    return this.store.find("messages");
  }
});