title: Cryptic warning without any google results [In Simulator]
body: <p>I get this warning in my iOS project: (iOS7, XCode 5 GM)</p>
  
  <blockquote>
    <p>Warning: Unable to create restoration in progress marker file</p>
  </blockquote>
  
  <p>I am working on a viewcontroller that turns all black when I get this warning on startup.
  Deleting the app and restarting XCode sometimes seems to help. I am returning NO on both</p>
  
  <pre><code>-(BOOL)application:(UIApplication *)application shouldRestoreApplicationState:
  -(BOOL)application:(UIApplication *)application shouldSaveApplicationState:
  </code></pre>
  
  <p>Update1: I tested on iPhone4s. Same result. Warning and black screen on my view controller.</p>
  
  <p>Update2: Answered my own question for the black screen. The warning just disappeared in latest iOS 7.0.x versions.</p>