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Tickwise
CriticalPerformanceSIG-PA-002

Watchdog: the server has hung and will be stopped (The server has stopped responding!)

Platforms
Paper · Purpur · single server
Verified
Verified
Confidence
Confidence 95%

What it looks like in the log

Any one of these lines is enough. The agent matches them locally, on your server.

logs/latest.log
  • [ERROR] The server has stopped responding!

Symptoms

  • The server stopped responding, players timed out, then the process stopped/restarted
  • In the log: “The server has stopped responding!” and a Server thread dump

Cause

The server's main thread did not finish a tick within timeout-time from spigot.yml (60 s by default); the watchdog printed a thread dump and is stopping the server. The culprit is usually visible in the Server thread frames.

Possible causes

  • A plugin is blocking the main thread (synchronous HTTP/SQL request, infinite loop, deadlock)
  • A huge world operation (WorldEdit, an explosion/redstone machine, saving the world on a slow disk)
  • Resource shortage: host CPU/disk, an OOM-related GC pause

How to fixLow risk

  1. In the Server thread dump, find the first frames belonging to a plugin (the plugin's package/jar) — that is the most likely culprit; sun.nio/java.net/com.mysql frames nearby indicate a blocking network request.
  2. Update or temporarily disable that plugin; report it to the author with the dump.
  3. If the dump shows world/chunk saving, check the disk (free space, speed) and do not run heavy WorldEdit operations on a live server.
  4. Do not increase timeout-time in spigot.yml as a “fix” — it turns crashes into long hangs.

Translated from the Russian original; log lines are quoted verbatim.

Sources