Whether killing through using a sword, bed, or command, the instant the dragon dies the game crashes. Upon rejoining, everything seems fine (gateway opened, XP dropped, etc.) however the issue is still annoying. I have tried both with a full modpack and by itself, yet the issue persists so the issue seems to be within the mod.

Attached is the crash report:
crash-2021-05-21_18.06.11-client.txt