How to Fix FrozenLib Crashes and Missing Dependency Errors

FrozenLib is a library mod, which means it does nothing on its own but is required by other mods. Most problems players hit are dependency-related rather than bugs in FrozenLib itself.

"Missing or unsupported FrozenLib" on Launch

This means a mod you installed expects FrozenLib but can't find a compatible copy. Check your mods folder and confirm FrozenLib is present. If it is, the version likely doesn't match the mod requesting it — the dependent mod may need a newer or older FrozenLib build. Remove the mismatched copy and add one that matches the dependent mod's requirements.

Crash on World Load

If the game launches but crashes when opening a world, a dependent mod is probably trying to use a FrozenLib feature (custom scheduled ticks, datafixers, or structure path changes) that doesn't match your world's data. Back up the world first. Then check whether you recently added or removed a mod that uses FrozenLib — removing such a mod mid-world can leave references that FrozenLib can't resolve.

General Troubleshooting Steps

Read the crash log's top lines; they usually name the offending mod. Disable dependent mods one at a time to isolate the culprit. Keep FrozenLib and all dependent mods from the same source and matching game version. Don't mix builds from different loaders.