title: Xcode: "Scene is unreachable due to lack of entry points" but can't find it
body: <p>Xcode 4.5.2 gives me the following warning:</p>
  
  <pre><code>Unsupported Configuration    
  Scene is unreachable due to lack of entry points and does not have an identifier 
  for runtime access via -instantiateViewControllerWithIdentifier:.
  </code></pre>
  
  <p>Unfortunately I can't identify the incriminated scene. Selecting the warning in the Issue Navigator doesn't highlight anything in the Storyboard. I have a fairly complicated storyboard (30+ scenes). </p>
  
  <p>Any suggestions?</p>
  
  <p><img src="https://i.stack.imgur.com/6lncL.png" alt="Screenshot for warning"></p>