During the Dead King fight, the boss summons zombies and skeletons from the ground. Not entirely sure when but the game crashes soon after that. The only other mods are Jade (WAILA) and JEI. Logs are attached.

Attachments:
crash-2023-09-22_15.21.18-server.txt
latest.log

Just read the log. I know what the issue is, will be fixed in the next update. Thanks for posting. 👍