[1.20.1][Forge] Crash with Immersive Overlays

[Bramblejack]

Describe the Bug

crash-2026-03-08_23.22.15-client.txt

Trying to access any entry in the Field Guide will lead to this crash.

Reproduction Steps

1. Open the field guide
2. Open any entry
3. Crash

Expected Result

No crash

Screenshots and Videos

No response

Operating System

Windows 11

Mod Version

1.1.3

Minecraft Version

1.20.1

Mod Loader

Forge

Other Mods / Modpack

No response

Additional Context

No response

[evanbones]

Can you try 1.2.0? I think this issue should be fixed in that version

[Bramblejack]

With 1.2.0 I can't even enter the world anymore.

crash-2026-03-09_12.02.42-server.txt

[Bramblejack]

Okay, I've figured it out - it was a biome_modifer I had in my datapack that was referencing "environmental:snowy_pine_slopes" which does not exist. So technically it's fixed, but you may want to look into how the mod iterates through biome list, because it seems that it picks up non-existing references as well and this may cause issues with other datapacks.