I am having the same problem, with pretty much all purchased worlds not loading, only default worlds and the christmas town for some reason.
Same problem on Windows 10 here, dozens and dozens of worlds are no longer accessible after 1.12.0 and 1.12.1 didn't help either. Is there any official response?
Same problem on Windows 10 here, dozens and dozens of worlds are no longer accessible after 1.12.0 and 1.12.1 didn't help either. Is there any official response?
That was the first thing I tried, without luck.