IrisFixes Mod (1.20.1 ,1.20) patched a specific bug in Iris for older Minecraft versions. It’s fix ConcurrentModificationException in SodiumCoreTransformer when processing vaUV2 identifiers by creating a copy of the list before iteration and deletion.
Features:
- Fixes a ConcurrentModificationException in SodiumCoreTransformer when processing vaUV2 identifiers.
- Achieved by creating a copy of the list before iterating and deleting, preventing runtime crashes.
- Designed for Minecraft versions no longer supported by Iris, especially in modded environments.
Screenshots:
IrisFixes Mod Download Links
For Minecraft 1.20.1, 1.20
Fabric version: Download from Server 1 – Download from Server 2
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.20.1, 1.20
- 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: In MC Java Mods, or directly above on this page.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
Verified by MCModsHub
- Downloads as 176543.mcaddon
- Download size: 8 KB
- Download link checked 25 Jul 2026 — working
- Mirrored on our own servers — the download does not depend on the original host
These come from our own check of the pack file, not from the source page.