I have an Xbox One.  I updated Minecraft on October 5.  The update took 2 days(Oct. 5-6). It never finished.  It just stayed in the finalizing screen.  I powered off the system and left it alone until the next day(Oct.7). When I turned the console back on the game wasn't showing any updates and was able to load.  I logged in and everything was missing.  All my worlds and skins were gone.  I uninstalled Minecraft, hard reset the system, reinstalled Minecraft, and hard reset the system again.  I have actually done this twice.  Support from Mojang told me to try it again.  Once the game reinstalled I logged back in.  My skins were there.  My worlds were there also, however all of them were gray.  None of my worlds will sync.  Most say "World cannot sync".  One of the worlds, which is a copy of my original world says "The world is not fully synced or has been corrupted. Try playing the world on a console where it's in a good state and try migrating it again".  I included a screenshot of the one world that says it's corrupted.  Please look in to this.  I have almost a year invested into my current world and would be devastated if I had to start all over from scratch.