Concurrent Chunk Management Engine - Forge

C2ME-Forge 0.2.0-forge.9.3 (Minecraft 1.20.1) - build 2026-09-16

Hotfix for forge.9.1 and forge.9.2 - fixes the permanent server freeze and a crash on entering the Nether. Nothing else.

Fixed
• Servers could freeze permanently - no chunks loading, mobs and machines stopped, TPS zero, while the client kept drawing so you could still move and look around, and no crash report was written. While a chunk is being promoted to a full chunk, Minecraft fires the chunk-load event and registers block entities; a mod that asks for that same chunk from in there (Dimensional Doors does, for every pocket chunk) waited on a future that could only complete once its own code returned. The blocking chunk request now hands back the chunk being loaded, and the same bypass covers entity loading, so chunk-load and entity-join handlers in any mod are safe
• Vanilla Forge has the same gap. Most 1.20.1 packs get this protection from ModernFix, whose chunk-deadlock fix C2ME has to switch off because the rest of it rewrites the same chunk code - so packs running C2ME were left without it. It is now built into C2ME-Forge
• forge.9.2's scheduler fixes (the lost wakeup and the nested-request priority marker) remain in place
• Hard crash on entering the Nether alongside Better Chunk Loading, seen as a "ticking player" kick from Neruina: IllegalArgumentException: Already scheduled, out of C2ME's chunk loader during the portal search. Better Chunk Loading's optimizeWaiting (on by default) requests a chunk's load a second time while the server waits for it, which vanilla accepts and C2ME rejected. A duplicate request now joins the load already in flight
• Both faults are inherited from upstream C2ME

Chunk system only - generation order and worldgen output are unchanged, existing worlds unaffected. Kill switch: -Dc2me.disableModule.fixes.general.deadlock=true
Drop-in update - recommended for everyone on forge.9.x, and required if you use Dimensional Doors or Better Chunk Loading. No config changes needed.
Support: https://discord.gg/s7BYs6Njj5