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warningJava ErrorsAffects: All versions

How to Fix java.lang.IllegalArgumentException

Fix IllegalArgumentException in Minecraft by resetting the offending mod's configuration file to default values.

Quick Fix

Reset the configuration file for the mod shown in the stack trace.

Error Message

java.lang.IllegalArgumentException

How to Fix

1

Delete and regenerate the config file for the offending mod

2

Verify resource packs are formatted correctly

3

Check NBT data of problematic items or entities with NBTExplorer

4

Update the mod to the latest version

Common Causes

  • Invalid configuration values in a mod or plugin
  • Corrupted NBT data in world files
  • Invalid resource pack format
  • Mod passing wrong parameters to game methods

Diagnostic Steps

  1. Read the error message for what argument was invalid
  2. Check the associated mod's configuration
  3. Reset or correct the invalid value
  4. Restart the game

FAQ

Can I fix this without removing the mod?

Often yes. Reset the mod's config file and the error goes away. The config is usually in the config/ folder.

Related Errors

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