Versions

Betweenlands version:

3.5.1

Forge version:

forge-14.23.5.2847

Singleplayer or Multiplayer:

Multiplayer, vanilla server. (Could not reproduce in single player).

Installed mods:

Mod list: https://pastebin.com/aDdCa0K4
Modpack link: https://github.com/HeartlessAUS/Crisps-of-the-Multiverse/releases

Link to full crash log

https://pastebin.com/Guq7MWrk

Description of the problem

A client side crash occurs whenever a player triggers the "eye" that teleports the player to the top of the fortress and starts the boss fight agains the Primordial Malevolence. Players may rejoin the server and there is enough time to teleport them away from the source of the problem, but they will crash again if they approach the triggered boss fight.

How to reproduce:

1. Reach the fortress and obtain the shockwave sword.
2. Enter the final floor and stare into the "eye" thing (Crash can happen at any time after the bossfight triggers).
3. Additionally, approach the area where the fortress is once the boss is active to crash without staring at the eye.

Expected result:

Boss spawns, bossbar is visible, the area darkens and boss music plays.

Actual result:

The game crashes client side, but the server is completely fine.

Pictures:

Unable to provide any meaningful pictures, as they are all just a frozen screen before crashing.

This is caused by DrZharks MoCreatures. Has been reported a long time ago but unfortunately has not been fixed yet.