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Project Zomboid Mod Config Checker

Dedicated server won't start, or mods silently don't load? Paste your servertest.ini mod lines. We fetch every WorkshopItems= entry from Steam, work out what each one actually provides, and find the exact break - a mod with no Workshop item, a missing dependency, wrong load order, a Build 41 mod on a Build 42 server, a map missing from Map= - then hand you the corrected, startable config.

Only those three lines are read; the WorkshopItem IDs are checked against the public Steam Workshop. Don't paste passwords or RCON secrets - they aren't needed.

Want this on a real server? Supercraft hosts this game →

The five things that stop a modded PZ server from starting

Every check here is deterministic - IDs, dependency metadata, load order, build tags. We don't guess at whether two mods clash in Lua at runtime (that can't be proven from the config); we catch the structural breaks that actually stop the server booting:

  1. A Mod ID with no Workshop item. Mods= lists a mod that none of your WorkshopItems= provide. The server logs "mod not found" and stops. This is the single most common cause.
  2. A missing dependency. A mod needs a framework or patch mod that isn't in Mods= at all.
  3. Wrong load order. A dependency sits after the mod that needs it in Mods=. We reorder so dependencies come first, from the dependency metadata. Treat that as the intended order, not a guarantee. On Build 42.20 dedicated servers there are reports that the Mods= order is not always respected and that a mod's own loadAfter= declaration is what actually settles it. If a load-order problem survives our reordering, that is the next thing to look at rather than evidence the ordering was wrong.
  4. A Build 41 mod on a Build 42 server (or the missing B42 backslash on Mod IDs). Either way, nothing loads.
  5. A map mod whose folder isn't in Map=, so the map never loads even though the mod downloaded.

Building a fresh server from a collection instead of debugging an existing one? Use the Workshop Collection → Server Config tool. Want the whole thing hosted? Run a Project Zomboid server with Supercraft.

Where to find servertest.ini

On the server host it lives in ~/Zomboid/Server/servertest.ini (Linux) or %UserProfile%\Zomboid\Server\servertest.ini (Windows). The three lines you need are WorkshopItems=, Mods= and Map=. Copy them exactly, including the semicolons.

Frequently asked questions

Why won't my Project Zomboid dedicated server start after adding mods?

The most common cause is a Mods= entry that no WorkshopItem provides - the server logs 'mod not found' and stops loading. Others: a missing dependency, a dependency loaded after the mod that needs it, a Build 41 mod on a Build 42 server, or a map mod whose folder isn't in Map=. This checker fetches each of your WorkshopItems, finds which of these applies, and returns the corrected lines.

What's the difference between WorkshopItems= and Mods=?

WorkshopItems= is the list of numeric Steam Workshop IDs the server downloads. Mods= is the list of text Mod IDs it then loads. One Workshop item can contain several Mod IDs. If a Mod ID in Mods= has no matching WorkshopItem, the server can't find it and fails - that mismatch is the number-one startup failure.

Why do my Build 42 mods fail to load even though the IDs look right?

Build 42 requires a backslash before every Mod ID in the Mods= line (the semicolon separator is unchanged). A Build 41-style Mods= line pasted into a B42 server loads nothing. The corrected config this tool gives you is already in the B42 backslash format, with a plain Build 41 version underneath.

Does this upload my server files or passwords?

No. It reads only the WorkshopItems=/Mods=/Map= lines you paste and queries the public Steam Workshop for those item IDs. Don't paste passwords or RCON secrets - they aren't needed and are stripped from anything stored.

This tool: v1.8 · updated 10 Sep 2026