title: Cakephp 3.2.6 admin prefix - Error: The application is trying to load a file from the Admin plugin
body: <p>I am struggling from the migration of my 2.0 cakephp site to 3.2.6. I followed the cookboo on how to implement an admin section of my site. When link to my admin section I receive: Error: The application is trying to load a file from the Admin plugin. Below are my codes:</p>
  
  <p>\config\routes.php</p>
  
  <pre><code>Router::prefix('admin', function ($routes) {
  // All routes here will be prefixed with `/admin`
  // And have the prefix =&gt; admin route element added.
  $routes-&gt;fallbacks('DashedRoute');
  });
  </code></pre>
  
  <p>\src\Controller\Admin</p>
  
  <pre><code>namespace App\Controller\Admin;
  
  use App\Controller\AppController;
  
  /**
  * Quads Controller
  *
  * @property \App\Model\Table\QuadsTable $Quads
  */
  class QuadsController extends AppController
  {
  
  /**
   * Index method
   *
   * @return \Cake\Network\Response|null
   */
  public function index()
  {
      $this-&gt;paginate = [
          'contain' =&gt; ['Users', 'Categories', 'Genres', 'Venues']
      ];
      $quads = $this-&gt;paginate($this-&gt;Quads);
  
      $this-&gt;set(compact('quads'));
      $this-&gt;set('_serialize', ['quads']);
  }
  </code></pre>
  
  <p>All of my .ctp files are in \Template\Admin. </p>