Hello,
First off, this is an amazing mod. Thank you for your time and effort for putting a mod like this together. nothing comes close to this. With that being said currently have an issue;

A player within our server was flying around with the Elytra and as soon as he turned on fight mode the server crashes. I have several crash reports that coincide with each other. Server crashes when he flies with fight mode on. Also when he tried to log back in afterwards server crashes again. After taking out epic fight mod he is able to log back in and continue as normal. We added the Epic fight mod and restarted. He was able to join no problem again. to confirm that was the issue he tried it again and you might guess, the server crashed again. Here are some crash reports from it. Let me know what else i can do to help test any issues so we can fix it. Thank you for your time in advance!

Spec:
Minecraft Forge: 36.1.0
Minecraft Version: 1.16.5

crash-2021-05-21_22.09.06-server.txt
crash-2021-05-21_22.15.00-server.txt
crash-2021-05-21_22.30.15-server.txt
crash-2021-05-21_22.50.51-server.txt
crash-2021-05-21_23.26.13-server.txt
crash-2021-05-21_15.39.03-server.txt
crash-2021-05-21_22.04.55-server.txt