strange issue
Same issue.
Error occurs when player tried to join a hosting world have any form of datapacks, not ensure if it happens in pure vanilla side.
Block user
Please note that blocking a user has other effects, such as:
- You will stop following each other and will not be able to follow each other.
- This user will not be able to interact with the repositories you own, or the issues and comments you have created.
- You will not be able to add each other as repository collaborators.