title: executeFetchRequest:error: A fetch request must have an entity
body: <p>I had a project that was working fine.  It had "Core Data" checked, and had the data model all set up. I only started adding a couple entities and properties tonight.  When I try to run my app now, it won't even load.  It just crashes on me.  </p>
  
  <p>Here's the error:</p>
  
  <p><code>'NSInvalidArgumentException', reason: 'executeFetchRequest:error: A fetch request must have an entity.'</code></p>
  
  <p>I'm really scared because I don't have a backup of this and if I can't get it working I don't know what I'll do. :)</p>
  
  <p>Thanks in advance!</p>
  
  <p><b>EDIT:
  I got fed up with my data, so I just copied a new blank xcdatamodel to my project and I'm going to start fresh.  Thanks for the help! </b></p>