Server setup

Scheduling chunk load off-main (Folia Region Thread Error)

What the log looks like

java\.lang\.IllegalStateException: Scheduling chunk load off-main
failed main thread check: Scheduling chunk load off-main

How to fix it

  1. Update your Folia server JAR to the latest available build for your Minecraft version, as multiple vanilla mob pathfinding and AI goal crashes (including Sniffers, Bees, and ranged mobs) were fixed in Folia patches.
  2. Check the stack trace lines right above 'EntityScheduler' or 'FoliaEntityScheduler', or look for 'Entity task for <Plugin> generated an exception', to see if a specific plugin triggered the chunk load.
  3. Update that plugin to a Folia-compatible release, or remove it if it only supports standard Spigot/Paper single-thread scheduling.
  4. If you are the plugin developer and this occurs when opening a custom GUI (such as InventoryType.HOPPER), pass a custom InventoryHolder instead of null to Bukkit.createInventory() so the server does not try to load a real container block at 0, 0, 0.
  5. If multiple essential plugins keep throwing this error because they lack Folia support, migrate the server from Folia back to Paper, which runs all chunks on a single main tick thread.
LoadersServer
SeverityBreaks something
CategoryServer setup

Check your own log

Related errors

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