title: Only Custom segues support class names prior to iOS 9.0
body: <p>In Xcode 7 GM, I'm getting the above warning in my storyboard. What does it mean?</p>
  
  <p>I do have some Custom segues, and they have their class assigned to a transition manager (UIStoryboardSegue). I checked all my segues in the storyboard, and all the custom segues have a custom class, and all non-custom segues don't have a custom class assigned (including unwind segues).</p>
  
  <p>Any ideas?</p>