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criticalCrash ReportsAffects: Forge/NeoForge

How to Fix Mixed Mappings / Remapping Error

Fix Mixed Mappings by replacing development mod jars with release versions from official download pages.

Quick Fix

Download the release (not dev) version of the mod from CurseForge or Modrinth.

Error Message

Mapping conflict / Remap error / SRG/MCP name mismatch

How to Fix

1

Replace dev/deobf jar with the release/obf jar

2

Download from official mod page, not GitHub releases

3

Ensure you are not using a -dev or -sources jar

4

Update the mod to the latest release build

Common Causes

  • Mod compiled with different obfuscation mappings
  • Development build of mod used in production
  • Mixed SRG and MCP mappings

Diagnostic Steps

  1. Check the mod jar filename for 'dev' or 'deobf'
  2. Download the regular release jar
  3. Replace the file in mods/
  4. Restart

FAQ

What are mappings?

Minecraft code is obfuscated. Mappings translate readable names to obfuscated ones. Dev jars use readable names that do not work in production.

Related Errors

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