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criticalCrash ReportsAffects: All versions

How to Fix ConcurrentModificationException in World Tick

Fix ConcurrentModificationException in world tick by updating the buggy mod or plugin.

Quick Fix

Identify the mod or plugin from the stack trace and update it. This is a threading bug.

Error Message

java.util.ConcurrentModificationException during world tick

How to Fix

1

Update the mod or plugin shown in the stack trace

2

Report the bug to the developer

3

Remove the mod if no fix is available

4

Use a server fork with better thread safety (Paper)

Common Causes

  • Mod modifying entity list during iteration
  • Plugin accessing world data from async thread
  • Race condition in world processing

Diagnostic Steps

  1. Read the crash report stack trace
  2. Identify the mod/plugin
  3. Update it
  4. If no update, remove it

FAQ

Can I fix this without removing the mod?

Only if an update is available. This is a code bug that requires a fix from the developer.

Related Errors

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