Place down a command block.
Open the command block UI.
Fill the entire command block's input line with this emoji:
✌And I mean COMPLETELY fill the input. Paste the same emoji over and over again. I'd paste the entire sequence here, but it makes this report exceed the 20k character limit.
Save and quit from the world.
Reload the world.
Chunk should be reset to original world generation. World may possibly crash, as seen here: https://www.youtube.com/watch?v=C4t2avl0Dhw
World may also be missing from the list of worlds when saving and quitting, but restarting the client seems to bring it back.
Thank you for your report!
We're tracking this issue in MC-220067, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
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