How to Install Steam Workshop Mods on Your Project Zomboid Server

Project Zomboid mods come from the Steam Workshop. The server needs two different identifiers for each mod, and getting them mixed up is the single most common cause of a server that will not start after modding.

The two identifiers

• The Workshop ID is the number in the workshop page URL, for example 2392709985.
• The Mod ID is a name the author sets, listed on the workshop page description, for example Authentic Z or tsarslib.

One workshop item can contain several Mod IDs. The description will say so.

Add the mods

1. Stop the server. Project Zomboid rewrites the INI on shutdown, so editing it while running loses your changes.
2. Open Files and edit:

   Zomboid/Server/servertest.ini

3. Set the two lines, semicolon separated, no spaces around the semicolons:

   WorkshopItems=2392709985;2169435993;2200148440
   Mods=AuthenticZ;tsarslib;Brita_2

4. Save and start the server.

The server downloads each workshop item on start. The first start after adding mods takes noticeably longer.

Load order matters

Mods load in the order they appear in Mods=. Library mods and frameworks that others depend on must come first. If a mod page lists requirements, put those requirements before it.

Map mods need a third line

A map mod also has to be added to the Map= line, ahead of the base map:

Map=Lake Ivy Township;Muldraugh, KY

Muldraugh, KY stays last. Anything before it takes priority. Adding a map mod to an existing world only generates the new area where players have not already explored, so a fresh world is cleaner.

Your players need the same mods

Every player must be subscribed to the same workshop items. Project Zomboid normally prompts them to subscribe when they join. If a player is stuck at Connection lost during loading, they are missing a mod or running a different version.

When a workshop update breaks the server

Steam updates workshop items automatically and the server picks up the new version on restart, which can break a running save. From the panel console:

checkModsNeedUpdate

reports whether anything has changed. If the server crashes on start after an update, remove the last mod you added from both WorkshopItems and Mods and start again.

Removing a mod

Take it out of both lines. Removing a mod that added items or vehicles leaves gaps in the save, so back up Zomboid/Saves/ from Files before you do it.