I have my suspicions that foamfix is having an incompatibility thing going on here since I saw its name mentioned.

My bad if Im wrong.

Happens short after someone enters the Nether while on my server, a couple of steps in. Never happened during Single players tests.

https://gist.github.com/Sereath/e3176114d057179cde30eb53e0302996

https://gist.github.com/Sereath/7a6f59ab8da9352e372c63b6e0e33a33

Latest log:

https://gist.github.com/Sereath/504cdbdc85e43c44ce8b39f68cf47d33

Debug log:

https://gist.github.com/Sereath/5fa00ef1425160b9e9ca44e8c6186299

By the way, are we still fine with running Foamfix along with ASM? Or is Foamfix getting redundant.

Edit:

Seems to happen when loading and unloading certain chunks, because the moment everyone leave the server instantly crashes the same way. Might even be a completely different mod at this point doing bad things.

Edit:

Might be Nether Portal Spread. I'll continue with my tests.

Had this issue back then in 2019 with Nether Portal Spread.

https://gist.github.com/Sereath/1241c04796ac049d167bc5a10a3010a4

https://gist.github.com/Sereath/4de2b8b409eef88aa7fe9104a9665cb5

And this issues started soon after we opened our first Nether portal. I'll have to test if for some time without it. Hopefully this is the culprit.

Do you have fasterEntityDataManager turned on in foamfix's configs?

Glad to see you found a fix

It was off.

Either way I havent been able to reproduce the issue ever since I did something about Nether Portal Spread and its library Collective.
Closing this now since there wasn't really any problem between Foamfix and ASM.