After downloading the update (1.12.0), I logged on to a single player world to check it out, nothing out of the ordinary happened. I logged out and the next day I see that I can't join any of my singleplayer worlds. The progress bar simply fills 100% and stays this way forever. No freezing, just infinite loading.
Comments 2
Cleaning up old tickets: This ticket has not been updated recently (~1 year+) so is being closed as Cannot Reproduce. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines.
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This happened to me too when I updated my game to update 1.12, except I was on iOS.Hopefully mojang listens and fixes this in the next update soon.