I had created a new world after deleting one and it froze at "converting world". I ended it through task manager. And saw the error in the log.
The world was able to load the second time.
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Please attach the log/crash report.
Attached the log of the console. Cannot paste it as a comment since there is a 20000 charater limit 😞
Edit: See there is a crash report, will upload later today.