title: QFileDialog::getOpenFileName always returning null
body: <p>This is really stumping me, it was working before hand but now it always returns null (therefore not populating).</p>
  
  <p>The code at question is:</p>
  
  <pre><code> imgObjPth = QFileDialog::getOpenFileName(this, tr("Select Image"), PATH);
  </code></pre>
  
  <p><code>imgObjPth</code> is a <code>QString</code> variable, and <code>QFileDialog</code> returns <code>QString</code>. So how come it's returning null? As I said, this line of code has worked in the past, so I just don't know why today it decides not to work.</p>
  
  <p><strong>Edit</strong>: </p>
  
  <ul>
  <li>Cancel is not being pressed. </li>
  <li>I've moved my development from Mac to Ubuntu, but the same issue occurs on my Mac too.</li>
  <li>QT 5.4.2 is used</li>
  </ul>