Invalid datapack, can't load world

[PlovieJ]

Minecraft Version

1.20.1

Mod Version

1.20.1-0.10.1

Describe the bug!

Even though I haven't updated a single mod and the world loaded just fine two days ago (last time I played), the world refuses the load now, claiming invalid datapack.

The last lines in the log are all about morejs before throwing the error and refusing to load the world.

Latest log and forced crash report included (forced crash via ATM9 modpack)

Crash Report

https://gnomebot.dev/paste/mclogs/iSz3FQW

Log

https://gnomebot.dev/paste/mclogs/EkrMYrk

Additions and Modifications

Yes

Additions and Modifications Description

I added a few mods to the ATM9 modpack and updated a few. List here: https://gnomebot.dev/paste/mclogs/Pe7dtRA

However, the world has loaded just fine several days in a row.

Did the issue happen in singleplayer or on a server?

Singleplayer

[LLytho]

Hey,

please report that issue to ATM. Sounds like a general class loading issue and MoreJS just don't randomly stops loading a class. I also checked the MoreJS jar and it looks correct for loading the classes.