Minecraft Version

1.20.1

What happened?

Just tried to open the inventory while playing medieval MC [FORGE] MMC4 1.20.1 v31 HF

Shoulve just opened the menu

How do you trigger this bug?

1.Launch game
2.Open server
3.Press E
4. Crash
...

Loader

Forge

Loader Version

Forge - 47.3.29

API Version

No response

Mod Version

Polymorph-forge-0.49.8+1.20.1.jar

Relevant Log Outputs

(https://mclo.gs/6VN2nz3)

Hello, I'm having the same issue, is there any way to fix it?

same issue in the crash log and it happens randomly at times, most of the time opening my inventory does as expected and sometimes it causes the this.next is null crash and most of the time that it happens I didn't change anything in my inventory between opening it and it working fine and opening it and it crashing

E.G. opening chests to look for a building block and then opening my inventory without adding or removing anything and then bam a crash

this crash involving "this.next" also looks be occurring on other versions and modloaders as well such as on 1.21.1 and neoforge as referenced here -> #302