Server freezes or watchdog kills it

The server freezes and then "The server has stopped responding" or the watchdog kills it.

One tick took too long: a huge operation, an infinite loop in a plugin, or a stuck chunk.

Before you start: The thread dump the watchdog prints in the console/log.

Step by step

1. Open logs/latest.log and find "The server has stopped responding". Below it is a thread dump.
2. Look at the main "Server thread" part: the first lines outside Minecraft's own code name the plugin or action.
3. Common causes: WorldEdit operations that are too big, a plugin loading data on the main thread, chunk generation stalls.
4. Update or remove the plugin named there.
5. Do large edits in smaller pieces, and pre-generate the world.
6. If it happens during a backup or restore, schedule those for quiet times.

Check it worked: No more freezes or watchdog stops.

Why it happens: The watchdog stops a server that has not ticked for 60 seconds.

If the dump points at no plugin, send support the log.

More guides on Crashes, startup failures, and errors:

• Find and read crash reports and logs
• Server stuck in a restart loop or will not start after an update
• Java version errors
• Failed to bind to port or unable to access jarfile
• Crash or error caused by a plugin
• Crash caused by a mod