title: Xcode storyboard doesn't show scene
body: <p>After finishing work on one of my screens in my swift project yesterday. I came back to modify it today and saw this:
  <a href="https://i.stack.imgur.com/hhx7Z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hhx7Z.png" alt="screenshot" /></a></p>
  
  <p>The screen is still working properly at runtime, I have no idea what could cause this. (Xcode 6.1, iOS 8.2)</p>