title: Presenting a NIB Modally Crashes on iOS 8 but not on iOS 9+
body: <p>I have created a NIB which has a name of <code>SomeViewController</code> and all the corresponding code are correct and all the views are bound correctly, but somehow the code <code>self.presentViewController(SomeViewController(), animated: true, completion: nil)</code> causes a crash:</p>
  
  <blockquote>
    <p>fatal error: unexpectedly found nil while unwrapping an Optional value</p>
  </blockquote>
  
  <p>What is the problem?</p>