title: Xcode 8 hangs on startup; [MT] DVTAssertions Warning
body: <p>I needed to work on my app in a different orientation, so I opened my main storyboard and selected the appropriate size class. Xcode froze up, and from that moment forward, I haven't been able to do anything in my project at all. Xcode hangs whenever it opens because it tries to open the storyboard. I checked the console to see what was happening and this message is repeated: </p>
  
  <blockquote>
    <p>[MT] DVTAssertions: Warning in
    /Library/Caches/com.apple.xbs/Sources/DVTFrameworks/DVTFrameworks-11224.1/DVTKit/LayoutViews/DVTLayoutView_ML.m:401
    Details:  An instance of IBUIViewControllerEditorView observed 5
    non-integral frame changes in a row for an instance of IBUIView with
    superview IBUIViewControllerEditorView. Further automatic layout
    invalidation has been canceled. Object:<br>
     Method:<br>
    -_invalidateLayoutIfNeededAfterRegisteringRectChange:forView:table: Thread:   {number = 1, name = main}</p>
    
    <p>Please file a bug at <a href="http://bugreport.apple.com" rel="nofollow">http://bugreport.apple.com</a> with this warning message and any useful information you can provide.</p>
  </blockquote>
  
  <p>Has anyone encountered this?</p>