How to Add Mods to Your Project Zomboid Dedicated Server in 2026
Vanilla Project Zomboid is an incredible survival simulation, but the Steam Workshop modding community elevates the game to a masterpiece. From expansive firearm overhauls like Brita's Weapons to massive custom maps like Raven Creek and Bedford Falls, mods are essential for keeping a long-term multiplayer server exciting.
However, installing mods on a Project Zomboid dedicated server is incredibly notorious for causing headaches. A single typo in your server configuration file can lock players out with a "Workshop Item Version Differ" error, or worse, permanently corrupt the map. In this comprehensive 2026 guide, we break down exactly how to install, order, and maintain mods on your hosted server.
Build 42 notes (2026): Project Zomboid Build 42 is the current stable branch. The two-line mod config (Mods= and WorkshopItems=) works the same as in Build 41, but a few details changed:
- Many B42 mod packs ship multiple Mod IDs per Workshop item. The mod's Workshop page lists each one; you must include all of them in your Mods= line, separated by semicolons, even though there's only one Workshop ID.
- Mod author conventions have tightened: most B42 mod pages now print the IDs in a copy-friendly block at the very bottom of the description.
- Client and server must be on the same branch (default / unstable). A B42-stable client cannot join a B42-unstable server even with identical mods.
The Two Critical INI Variables
To integrate mods on a dedicated server (like those running on Supercraft), you do not download the files manually via FTP. Instead, you instruct the server to download them directly from Steam during boot.
In your server's configuration directory (usually `/Zomboid/Server/`), open your servertest.ini file. You are looking for two specific lines:
Mods=(The internal Mod IDs)WorkshopItems=(The Steam Workshop IDs)
Both lines must be populated accurately. The WorkshopItem ID tells the server what file to download from Steam. The Mod ID tells the server which specific mod packet within that download to activate.
Finding the IDs
Navigate to the mod you want on the Steam Workshop (e.g., "KI5's 1993 Ford F-350"). Scroll to the very bottom of the description. The author will always list the IDs:
Mod ID: 93fordf350
Workshop ID: 2933758364If you are adding multiple mods, separate them cleanly with semi-colons (;) and no spaces.
Mods=93fordf350;TsarMotorHome;BritaWeaponPack
WorkshopItems=2933758364;2392987599;2200148440Installing Custom Map Mods (The Tricky Part)
Adding vehicle and weapon mods is easy. Adding complex map mods (like Blackwood or West Point Expansion) requires a third step, as you must explicitly tell the server to stitch the new map files into the vanilla Knox Country.
Locate the Map= line in your servertest.ini. The order here is critical. The vanilla map `Muldraugh, KY` must ALWAYS be at the very end of the list, as the server reads from left to right. Custom maps load their chunks on top of the base map.
Map=RavenCreek;Blackwood;Muldraugh, KYNote: If the map mod author specifies a specific spawn region folder, you must exactly type that folder name inside the `Map=` line.
Fixing the "Workshop Item Version Differ" Error
This is the most common error in Project Zomboid multiplayer. It happens when a mod author updates a mod on Steam, but your dedicated server is still running the old version, while the connecting player's client automatically downloaded the new version.
The Solution:
- Log into your hosting control panel.
- Completely shut down the Project Zomboid server.
- Restart the server. Upon boot, the server engine will check the Steam Workshop API, notice an update is available, and automatically pull the fresh files before opening the port to players.
To prevent this from occurring randomly while players are online, it is highly recommended to schedule an automated server reboot every 12 to 24 hours.
Handling Mod Dependencies
Most multi-part mod packs have dependencies. A common pattern is a shared library mod that several other mods build on top of, the most-cited example being ModOptions, which dozens of gameplay mods register their settings into. If you add a mod that depends on ModOptions but forget to install ModOptions itself, the server will either crash on world setup or fill the bottom-right corner with red error boxes.
Always verify your mod load order recursively against the "Required Items" sidebar on the Steam Workshop page. Add the dependencies before the mods that need them in both Mods= and WorkshopItems= lines.
The Easier Way: Skip the INI Editing
Manually editing semi-colons into a massive text file for a 150-mod pack is incredibly tedious and highly prone to human error (a single misplaced character will break the entire list).
If you host with Supercraft, the panel's Mod Manager handles this for you. You search the Steam Workshop by name from inside the panel, see mod cards with author, image, and Steam ID, and click to add. The panel writes the correct Mods= and WorkshopItems= lines into your servertest.ini behind the scenes. There's an "Only Maps" filter when you want to find a map mod fast, and dependencies still need to be added separately, but no INI editing is required.
Conclusion
Mods transform Project Zomboid from a great game into an endlessly replayable phenomenon. As long as you carefully manage your `servertest.ini`, respect dependency chains, and place the vanilla map at the end of your map string, you can sculpt the exact zombie apocalypse your community desires.
Don't waste hours chasing INI syntax errors. Start customizing your apocalypse instantly by grabbing a dedicated Project Zomboid server from Supercraft today.