Timed out on a Minecraft server: what it means

1Two sides of the same message

While a player is in the game, the game and the server keep sending each other small messages. When either stops for long enough, the connection ends with Timed out, the text Minecraft 1.21.1's language file gives disconnect.timeout.

On 29 Sep we joined a Paper 1.21.1 server with a test client, then froze the client's process at 14:03:56. The server dropped it 29 seconds later:

It's not the error you get joining: a server that can't be reached at all gives connection timed out or Connection refused before you're in.

2Which side went quiet

• One player drops while the others play on: that player's game or connection went quiet, as our frozen client did. A game that freezes, a Wi-Fi drop or a connection that loses packets for half a minute all end this way.
• Everyone drops at once: the server itself stalled, or its network did. Look in its log for Can't keep up! just before: generating new land put our test server 33 seconds behind, longer than the 29 seconds it gave our quiet client.
• The server stopped with a watchdog message after a tick that never finished: it froze, and it shuts itself down after a single tick takes a minute, the default max-tick-time of 60000 ms.

3What fixes it

• For one player: check their connection, and that their game has enough memory not to freeze.
• For the whole server: the fixes for lag. Pre-generate the map, give it a faster CPU and enough memory, and keep less of the world running.
• For a server that froze: a profiler such as spark, run while it lags, shows what takes the time.

4On a Playkeeper server

• The Overview shows who's playing and the server's ticks per second, so a stall shows next to the players it dropped.
• How it's running names what slows the server down, like players exploring new land, with the fix.
• A server that froze gets its own explanation on the Overview, with a button to start it again and a suggestion to run a profiler.