Spawn C2ME Fix
Java mod listed for Minecraft 1.20–1.21. Downloads from the MC Java Mods app on Android.
I don't know my version or loader
Description
This mod patches AnimalVariantManager.chooseWeightedVariant() in the Spawn mod to use the entity's own thread-safe RandomSource instead of Level.random.
This prevents a ConcurrentModificationException when C2ME calls finalizeSpawn from a worker thread during chunk generation, which would otherwise deadlock further chunk loading.
Known issues
The original approach was meant to make the animal variants deterministic, meaning you would always encounter the same variant in the same place in the world in the same seed. The fix breaks this behaviour and makes the variants completely random. Generating a world with the same seed will give you a different outcome each time.
There probably is a way to solve this more gracefully, but it would require much deeper integration which for me personally is out of scope.
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21.1, 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on CurseForge — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as spawn_c2me_fix-1.20.1-1.0.0.jar — drop this file into the mods folder
- Download size: 41 KB
- Download link checked 3 Oct 2026 — working
These come from our own check of the pack file, not from the source page.