title: Can't start iphone simulator; "not responding". Xcode 7, simulator version 9 (for iOS 9)
body: <p>Ever since i updated to the GM version of encode 7 I've been unable to use the simulator. I used to get an error, but when I updated to the official release (through app store) that stopped. Now it says "running [name of app] on iPhone [model]". When I look in the force quit menu it says not responding</p>
  
  <p>When I press "stop" it continues to show the same message. When closed and reopened it says "Build succeeded at... etc.", so I'm quite certain that the problem lies in the simulator and not the copy of xcode.</p>
  
  <p>I've tried projects that worked before, including one that I downloaded from the apple guide (I figured that would have to work if there was some problem with the code in my other projects).</p>