Crash reports#

Most things that go wrong in a place are script errors. A script indexes something that is nil, the error shows in the Output panel with the line it happened on, and the game keeps running. A crash is different: the engine itself hit something it could not handle, or the whole client or server stopped. There is no line of your code to jump to, and the person it happened to is often a player who has never seen your scripts.

When that happens Moud writes a crash report. It is a plain text file that says what happened in words, and it carries what someone needs to find the cause later without asking the player to describe it.

What a report holds#

A report from a server whose zone script got stuck in a loop looks like this:

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Moud crash report

What happened
  The server froze and was stopped while running a script
  One tick ran longer than the server allows. It was inside a script, and a loop that never waits is the usual cause.
Side      server
Time      2026-10-19 21:30:02
Place     Obby
Moud      ...

Last script errors
  server/zones.luau:42: PlayZone has been destroyed, it was World.Map.PlayZone
    server/zones.luau:42 in touched
    server/zones.luau:18

Trace
  java.lang.Error: Watchdog
    at ...

System
  OS        Linux 6.19.6 amd64
  Java      25.0.1 Eclipse Adoptium
  Memory    1130 MB used of 4096 MB
  CPUs      8
  Minecraft 26.1.2

Log
  ...

• What happened is one sentence in plain words. It is the first thing to read and usually enough to know where to look.
• Place and Time tell you which game and when, so you can match it with what players said.
• Last script errors are the errors the place printed just before, each with its Luau stack. A crash is often the end of a chain, and the error that started it is in this list.
• Trace is where the engine was when it stopped, for whoever works on Moud.
• System says what the machine was: the operating system, the Java it ran on and its memory.
• Log is the end of the game's log, the lines written right before the crash.

The report also names the Moud version that crashed. That is for you and for the people who work on Moud; players never see it in the game.

Where reports are written#

Clients and servers write their reports into the game folder:

<game folder>/moud/crash-reports/crash-2026-10-19_21.30.02-server.txt

The name ends in client or server, so a folder that holds both is easy to sort. On your own machine that is the folder Minecraft runs from. On a server started by a fleet it is that server's own folder inside the fleet's.

Sending a report from a client#

A client that crashes closes, and there is nobody to ask at that moment. The report waits in the folder, and the next time the game starts it asks once: Send report or Don't send. Nothing leaves the machine without the yes. Players who would rather not send anything still have the file on disk to share however they like.

Minecraft's own crash report, the one in crash-reports/, also gets a Moud line under System Details with the place and the last script errors, so a crash posted from a launcher is not missing the part that matters.

The engine can also break without the game stopping: a script calls into it and the engine fails, and the error in Output says so (see Finding bugs). That error has its own Send report button, which sends the same kind of report straight away.

Reports from your servers#

Servers started by a fleet send their reports on their own, with the fleet's token, so nobody has to press anything on a machine nobody is looking at. The report lands on your game.

Open your game's page on the website, then Settings, then the Crashes tab. It lists the crashes of the last 30 days, and the same crash from many servers shows up once with a count and when it last happened. A crash is the same crash when it stopped at the same place, the same line of the same script or the same spot in the engine, so ten servers dying on Zones.luau:42 are one row that says 10, not ten rows.

Click a row to read the newest report in full, with every other time it happened under it. Copy report puts the whole text on your clipboard, ready to paste into a forum post or an issue.

Only reports from your own servers show there. Reports that players send from their clients stay private to them and to the Moud team.

When it is not your game#

If a crash has nothing to do with your scripts, such as an engine trace with no Luau frame in it, it is worth telling the Moud team. Post the report on the forum. You can also check the status page first: when the catalog or the database is having trouble, it says so there, along with how the last 90 days went.