Xbox One CU13
I started playing Minecraft xbox one with my sister and she accidentally clicked add new account (she didn't have a Microsoft acct. she was trying to add a guest)
Clicking add new forced a game crash and took me back to the xbox one home screen.
As I reload minecraft, I notice I can't open any worlds.
The game allowed me to create a new world, so I create one and do the add new thing again.
I went to a different game, shut off the xbox one, waited 15 seconds, and turned it on.
I then reloaded minecraft.
Reloading minecraft and attempting to open the world resulted in the error "This save is corrupt or damaged."
This bug corrupts ALL of your worlds, no matter how old it is.
Because of this, I had to delete my redstone world which I spent almost a year working on it.
I'm not a scripting expert, but I believe parts of the code are not compatible with the changes Microsoft made recently with this console.
Thanks for your time
EDIT 1: This bug does not activate if the player hits "add guest"