Reproduction Steps

Not sure how to reproduce. Seems like after a few seconds after one my players join the server it crashes with this report below.
Can provide the current world if needed but it is a few gigs compressed.

Also using the build for 1.16.3

Crash Report File

https://gist.github.com/forrestw92/6c444c5abd5b033f3ba3e42df4c21f7e

Fixed in 014557c