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Quality Of Life Fixes Wiki › Guides › Fix Crashes When Placing Structures

Fix Crashes When Placing Structures

The Problem

When placing structures (like those from structure blocks or data packs), the game sometimes crashes with a ConcurrentModificationException error. This happens because the mod tries to read and modify structure data at the same time.

How This Mod Fixes It

Quality of Life Fixes resolves the ConcurrentModificationException that occurs in StructureTemplate.PalettedBlockInfoList. The mod makes the underlying data structure thread-safe, preventing the crash when structures are being processed.

When You'll Notice This

This fix helps if you:

  • Use structure blocks to place buildings or terrain
  • Load data packs with custom structures
  • Use mods that generate or place structures dynamically
  • Experience crashes when structures load in multiplayer

No action needed—this fix is automatic and requires no configuration.