title: CakePHP virtual field giving internal error
body: <p>In my Delivery model I have the following virtual field set:</p>
  
  <pre><code>public $virtualFields = array(
    'shoe_count' =&gt; 'SELECT COUNT(*) FROM shoes as Shoe WHERE Shoe.delivery_id = Delivery.id'
  );
  </code></pre>
  
  <p>When I remove this, everything works fine. Upon adding the shoe_count virtual field, I get the following error on any method of the Shoe controller:</p>
  
  <blockquote>
    <p>An Internal Error Has Occurred. Error: An Internal Error Has Occurred.</p>
  </blockquote>
  
  <p><img src="https://i.stack.imgur.com/Cpm7i.png" alt="enter image description here"></p>