The world is not fully synced or has been corrupted.  Try playing the world on a console where it is in a good state and try migrating it again.

I have reset the console.  Uninstalled minecraft and reinstalled it and also cleared the local data on my XBOX.  I have used this world for 3 years and no issues until I did a soft reboot on my console.   I need the communities help to get this world back.