Server setup

Folia IllegalStateException: Cannot asynchronously load chunks

What the log looks like

java\.lang\.IllegalStateException: Cannot asynchronously load chunks
failed main thread check: Cannot asynchronously load chunks

How to fix it

  1. Update Folia (or Folia-based forks like Luminol) to the latest available build for 1.21.4 or newer, which includes upstream fixes for entity block-collision checks during piston movement.
  2. If you are running a third-party Folia fork, test with an official PaperMC Folia jar to confirm whether the fork is missing upstream Moonrise thread-safety patches.
  3. Look for the log line `BlockEntity threw exception at <world>:<x>,<y>,<z>` directly above the stack trace to locate the exact piston or block causing the error.
  4. Clear any stuck ghost piston blocks at those coordinates by running `/setblock <x> <y> <z> minecraft:air` once a player is nearby so the region owns that chunk.
  5. Redesign or move piston mob pushers and teleport stasis chambers at that location so they do not push entities into unloaded chunks or across distant region boundaries.
LoadersServer
SeverityBreaks something
CategoryServer setup

Check your own log

Related errors

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