title: Core Data in swift. App loses data?
body: <p>I am confused by the way that my app is working.
  Main part of app is log of fuel fill ups with some statistics. It uses swift and core data.
  But for some reason on few devices sometimes it loses user data when app is closed (not putted to background)  - i can't understand why. Also i can't see it in emulator or on my devices.
  But some of my friends report me this error.</p>
  
  <p>My app is based on this example <a href="http://jamesonquave.com/blog/core-data-in-swift-tutorial-part-3/" rel="nofollow">http://jamesonquave.com/blog/core-data-in-swift-tutorial-part-3/</a>.</p>
  
  <p>My app is not translated to english so i don't know is it ok to put link to it here. </p>
  
  <p>How can it be that core data is empty when user closes app or reloaded his device?</p>