I downloaded 1.16 today and decided it was time to create a new world. I entered the seed, tested the world in single player to see if the seed worked, and then pressed "replace" on my original realms world. When I selected the world and started to export it it almost immediately caused an error and stopped exporting it.
Thank you for your report!
We're tracking this issue as REALMS-474, 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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