Project Zomboid server fixes

Permanent guides for the most common Project Zomboid dedicated-server log findings. Start with the matching error, then re-run the log analyzer on the fresh log tail.

Missing mod Fix Project Zomboid Missing Mod Errors

The server is trying to load a Mod ID that is not available on disk. Usually the WorkshopItems line, Mods line, or Steam Workshop download is out of sync.

Workshop download failed Fix Project Zomboid Workshop Download Failed

Steam could not fetch one or more Workshop items before the server started. The item may be private, deleted, blocked, or cached in a corrupt local folder.

Map load failure Fix Project Zomboid Map Load Failures

The server could not load a map folder listed in Map=. Custom maps need their Workshop item installed, their Mod ID enabled, and their map folder placed before Muldraugh, KY.

Port already in use Fix Project Zomboid Port Already in Use

The game server tried to bind a UDP/TCP port that another process is already using. Only one process can listen on the same IP and port.

Out of memory Fix Project Zomboid Out of Memory Crashes

The JVM ran out of heap while loading mods, maps, saves, or player data. Heavy modpacks often need more memory than the default startup script provides.

Not sure which guide applies?

Use the Project Zomboid Server Log Analyzer first. It matches the log tail, gives immediate next steps, and points you at the relevant fix.