title: bool _WebTryThreadLock(bool), 0xae8d250 error
body: <p>bool _WebTryThreadLock(bool), 0xae8d250: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now...</p>
  
  <p>My Code</p>
  
  <pre><code>dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{[self.navigationController pushViewController:aController animated:YES];
  });
  </code></pre>