title: Cakephp 3 : Json render View not working
body: <p>I've been trying to setup an Ajax Call in Cakephp 3.0.11.
  I've followed the explanation here : <a href="http://book.cakephp.org/3.0/en/views/json-and-xml-views.html" rel="nofollow">http://book.cakephp.org/3.0/en/views/json-and-xml-views.html</a></p>
  
  <p>Json enabled in routing (but i'm not really sure that's usefull) : </p>
  
  <pre><code>$routes-&gt;extensions(['json', 'xml', 'html']);
  </code></pre>
  
  <p>I've setup my exemple in controller : </p>
  
  <pre><code>$returnObject = new ObjectReturn();
  $this-&gt;set('returnObject', $returnObject);
  $this-&gt;set('_serialize', ['returnObject']);
  </code></pre>
  
  <p>But when I make my ajax call, I've got : </p>
  
  <pre><code>{
      "message": "Template file \Pages\\score.ctp\ is missing.",
      "url": "\/pages\/score",
      "code": 500
  }
  </code></pre>
  
  <p>If I create the page, he juste render me some html, with default.ctp as a layout. What's wrong here ?</p>
  
  <p>Thanks a lot !</p>