title: Dismiss a Modal UINavigation Controller
body: <p>I have a <code>UIViewController</code> (a) which is the root view controller in a <code>UINavigationController</code> (b). The <code>UINavigationController</code> is displayed modally (via a <code>segue</code>) from another <code>UIViewController</code> (c) that is completely separate.</p>
  
  <p>The issue I'm having is that when I try to dismiss the modally displayed vc (a) I get a black screen with nothing being displayed. I would have expected to see (c) displayed though.</p>
  
  <p>What is the correct way that I should be dismissing (a) which lives in (b) so that (c) is correctly visible afterwards?</p>
  
  <p>I have tried the following so far, none of which worked:</p>
  
  <pre><code>self.dismissViewControllerAnimated(true, completion: nil);
  self.navigationController!.dismissViewControllerAnimated(true, completion: nil);
  self.presentingViewController?.dismissViewControllerAnimated(true, completion: nil);
  </code></pre>