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warningJava ErrorsAffects: All versions

How to Fix java.lang.ClassCastException

Fix ClassCastException in Minecraft by resolving mod version mismatches and removing conflicting mods.

Quick Fix

Ensure all mods are compiled for the same Minecraft and mod loader version.

Error Message

java.lang.ClassCastException: class X cannot be cast to class Y

How to Fix

1

Verify all mods target the same Minecraft version

2

Update the mod loader (Forge/Fabric/NeoForge) to the latest version

3

Remove one of the conflicting mods

4

Check for known mod incompatibilities on the mod pages

Common Causes

  • Two mods providing conflicting implementations of the same class
  • Mod compiled for a different Minecraft version
  • Mixin conflict between mods
  • Incorrect mod loader version

Diagnostic Steps

  1. Read the ClassCastException message to identify the two conflicting classes
  2. Find which mods provide those classes
  3. Check both mods' compatibility notes
  4. Remove one or find a compatibility patch

FAQ

What does ClassCastException mean in Minecraft?

Two mods are trying to treat the same thing as different types. Usually a version mismatch or mod conflict.

Related Errors

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