title: UIImpactFeedbackGenerator not working
body: <p>I'm trying to use the new <code>UIImpactFeedbackGenerator</code> for haptic feedback, but it isn't working.</p>
  
  <ul>
  <li>Testing on iPhone 7</li>
  <li>iOS 10.1.1</li>
  <li>System Haptic setting is enabled</li>
  </ul>
  
  <p>I'm using the following code example in Objective-C  </p>
  
  <pre><code>UIImpactFeedbackGenerator *myGen = [[UIImpactFeedbackGenerator alloc] init];
  [myGen initWithStyle:(UIImpactFeedbackStyleMedium)];
  [myGen impactOccurred];
  myGen = NULL;
  </code></pre>
  
  <p>I'm triggering it inside a <code>UILongPressGestureRecognizer</code> delegate.</p>
  
  <p>Any idea what the problem might be?</p>