Install Project Zomboid modsThe two-key system: WorkshopItems & Mods

Published on August 4, 2026 · last updated on October 21, 2026

Why two lists?

A Project Zomboid server only loads a mod correctly when both entries are right:

• WorkshopItems - the numeric Workshop ID from the Steam URL. The server uses it to download the mod.
• Mods - the mod ID from the package's mod.info. This is what makes the game actually activate the mod.

If you forget one of the two lists, the mod is not loaded - without an error message. That is by far the most common pitfall.

The entries in servertest.ini

Both lists are in servertest.ini. You separate several entries with semicolons:

WorkshopItems=2200148440;2822286426
Mods=Bandits;ExampleMod

You will find the Workshop ID in the URL of the Workshop page. The mod ID is shown on the Workshop page under "Mod ID" or in the mod.info - a Workshop item can even contain several mod IDs, in which case you enter all of them.

Mind the load order

The order in the Mods list is the load order. Mods that build on others (frameworks, dependencies) belong in front of the mods that need them. In case of conflicts, the mod loaded last decides. Check the requirements of every mod on its Workshop page and enter dependencies first.

Conveniently via the Workshop editor

With our Steam Workshop editor in the panel, you maintain both lists without typos: add a mod, the IDs are taken over, done. After changes to the mod list, a server restart is required for the mods to be loaded. Custom maps are Workshop mods too and are entered the same way.

When a mod does not load

Project Zomboid does not clearly report missing mods - the server simply starts without them. This order leads to the cause the fastest:

1. Are both IDs there? A Workshop ID without a matching Mods entry is by far the most common case. Count through both lists - they do not have to be the same length, because a Workshop item can contain several mod IDs, but every mod needs its entry.
2. Is the mod ID exactly right? It is not the display name and not the Workshop ID, but the identifier from the mod.info. Upper and lower case count.
3. Was the mod downloaded? After the start, there should be a matching folder in the server's Workshop folder. If it is missing, the download did not work - usually because of a wrong Workshop ID.
4. Does the mod fit the build? A mod for Build 41 does not load reliably on a Build 42 server, see Build 42.

At startup, the server logs name every loaded mod. Comparing this list with your Mods entry shows within seconds which one is missing.

Changing mods on a running server

Adding mods is usually harmless: new items and vehicles simply appear as soon as the server knows them. Removing a mod, on the other hand, is the riskiest intervention of all - all objects from this mod disappear from the world, and areas in which they stood can be left damaged.

Maps and frameworks are particularly delicate. A removed map leaves holes in the terrain, a removed framework takes all mods built on it along with it. Once you have agreed on a collection, it is best to keep it until the end of the round.

Make a backup before every change to the mod list. Backups are self-service with us throughout: you fetch the save folder via WebFTP or SFTP, as described in Create backups. That keeps a way back open if the new collection does not work.

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