crash-2024-09-22_06.09.07-client.txt
Game Version 1.20.1
Crash occurs when any fluid containing item loads in creative menu/inventory.
Tried with multiple forge versions and fresh installs. z
For testing, Mekanism and Immersive MC were only two mods loaded.

Thanks for this report!

Same crash happening here with Immersive Engineering
Happens when clicking on the IE creative tab, removing the mod doesnt make it crash (Possible issues with items too that I havent checked)
crash-2024-10-16_13.33.21-client.txt

Have confirmed this (though I honestly had in the past in development, but thought it wasn't ImmersiveMC-related).

As a note to myself, this was introduced at some point during beta 2's development. Perhaps some Mixin isn't playing nicely with Forge?

This is now fixed, and will be in the next ImmersiveMC release!

Figured out the issue! Who would've thought mixing in a method named getFluid() into BucketItem would have zero consequences /s.

Fixing this should be fixed by #478, though to fix this issue specifically, renaming BucketItemAccessor's getFluid() method to something else (immersiveMC$getFluid() to do the right thing here) will fix this.