Every time I start up the game, it loads perfectly up until I reach the spinning background. At this point, the game tries to sync my user data, but is still trying after 3 hours.

Eventually I decided to cancel this seemingly infinite bug, but this simply left me stranded at the spinning backgroung with no buttons or anything.

I then tried to start up the game logged out of my xbox live account. This allowed me to get to the main menu. I then signed in and the user data sync started again, I left this for half an hour before cancelling and the game immediately began "signing in using [my] microsoft account". 

This worked but did not allow me to use any of my friends' or my realms and did not allow me to invite my friends to my worlds as my "device does not support realms".

Thank you for taking the time to read this, I hope I submitted this to the right department and that this issue is resolved soon.

If you need to contact me, please use my E-mail. Incase you need it, my xbox account is AvoidedBear8.