EntityGuardian
The author built this one for Minecraft 1.21.1 on NeoForge. On other versions it may install and then do nothing.
EntityGuardian is a lightweight stability mod that eliminates frustrating `ConcurrentModificationException` crashes during world ticking, specifically those occurring in Minecraft's entity management system. These crashes often happen when mods like Smoothchunk or server optimizers asynchronously modify entity data while the game is processing chunks.
Key Features:
🛡️ Crash Prevention - Patches `PersistentEntitySectionManager` to safely handle concurrent entity list modifications
⚙️ Zero Configuration - Works out-of-the-box without config files or user input
🔌 Wide Compatibility - Designed for Minecraft 1.21.1 (NeoForge) and compatible with most modpacks
⚡ Performance-Safe - Minimal overhead with efficient snapshot-based synchronization
How It Works
EntityGuardian uses targeted bytecode transformations to:
1. Replace unsafe entity list iterations with thread-safe snapshots
2. Prevent modification conflicts during chunk status updates
3. Maintain vanilla behavior while adding crash protection
Intented to fix FTB Skies 2 CME crashes, but works for anything else.
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.21.1
- 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 entityguardian-1.0.jar — drop this file into the mods folder
- Download size: 1.4 MB
- Download link checked 22 Aug 2026 — working
These come from our own check of the pack file, not from the source page.