Crash on Minecraft 1.21.8 – NoSuchMethodError in DataFixer

[Jamie314X]

Minecraft Version: 1.21.8
Chest Tracker Version: 2.6.7+1.21.4
Fabric Loader Version: 0.17.2
Other Mods: Multiple, but confirmed reproducible with Chest Tracker alone.

Description: When joining any server or loading a world, the game immediately crashes.
This only happens on Minecraft 1.21.8 – Chest Tracker works fine on 1.21.4.

Crash Log (relevant part): java.lang.NoSuchMethodError: 'net.minecraft.class_6595 net.minecraft.class_6489.method_37912()' at red.jackf.chesttracker.impl.datafix.Types.wrapInFixer(Types.java:24) at red.jackf.chesttracker.impl.memory.MemoryKeyImpl$Codecs.(MemoryKeyImpl.java:205) ... (FULL crash report attached below)

Steps to reproduce:

1. Install Chest Tracker 2.6.7+1.21.4 on Fabric 0.17.2 with Minecraft 1.21.8.
2. Join any multiplayer server or load a singleplayer world.
3. Immediate crash occurs.

Expected behavior: Game loads normally and Chest Tracker works.

Actual behavior: Immediate crash on world join due to NoSuchMethodError.

Additional context: It seems method method_37912 in net.minecraft.class_6489 has been renamed or removed in MC 1.21.8, causing incompatibility with the DataFixer logic in Chest Tracker.

crash-2025-08-12_14.11.07-client.txt

[mihoillo]

Mod isn't support 1.21.8 now, use alternative mods or run this on last supported version (1.21.4)

[xmorose]

@mihoillo what alternative mods are there?

[AlwaysHAK]

There's my updated version of ChestTracker & WhereIsIt. See [update] 1.21.6/7/8 for more information.