A friends realm stuck in 1.15.2

Put the summary of the bug you're having here

What I expected to happen was...: To be able to join the realm in 1.16
Describe what you thought should happen here

What actually happened was...: Loaded the old 1.15.2 version and it worked there insted
Describe what happened here

Steps to Reproduce: 1.open 1.15.2 2.Load realm 3.try loading in 1.16 4.be declined
1. Put a step by step guide on how to trigger the bug here
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