title: How can I fix NSInvalidUnarchiveOperationException
body: <p><strong>* Terminating app due to uncaught exception 'NSInvalidUnarchiveOperationException', reason: '*</strong> -[NSKeyedUnarchiver decodeObjectForKey:]: cannot decode object of class (NSLayoutConstraint)' </p>
  
  <p>I have a very simple app</p>
  
  <p>One view has one button</p>
  
  <p>I Control Click and dragged the button to a second view and selected MODAL</p>
  
  <p>When I run it in the simulator, everything works</p>
  
  <p>When i run it in my iPad running iOS 5.1.1, it crashes with the error above. I have no idea why and there is no code.</p>