Note: Probably affects other versions, but I haven't tested them.
Running {{/locate }}in a world without structure generation enabled stops entities from moving, spawning, or despawning; prevents item deletion in the creative inventory; and prevents commands from being run.
Normally, this occurs for just a few seconds after running /locate before the requested structure is found; on these types of worlds, structures can never be found, so the game continues looking until the it's forced to close (logging out keeps the game on the "Saving world..." screen until force closed).
The game output log is attached. The exact command I ran was /locate Nether_Fossil and it was run within the Nether on a superflat world without generated structures. At the end, I forced the game to crash with F3+C.
Thank you for your report!
We're actually already tracking this issue in MC-126244, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved as Fixed. The fix will arrive in the next version or is already included in the latest development version of the game.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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