Project Zomboid Build 42 Dedicated Server Setup (42.22.2 stable)
Build 42.20 went stable on 29 July 2026. B42 is no longer a beta branch you opt into, it is the supported build, and Project Zomboid passed its all-time peak player count the day it landed. If anything below describes B42 as unstable or upcoming, read it as history: the branch it refers to is now the default. The one live caveat is mods, since a lot of Workshop items have not been republished for stable yet, so a list that worked last week can fail today.
Build 42 is the biggest Project Zomboid update in years, and since 42.20 it is the default public build: you no longer opt into a beta to run it. The Unstable beta is gone: on 27 October 2026 The Indie Stone replaced it with the Pre-Release beta, which carries the next build ahead of public, so opt into pre-release only if you want that. Use this guide to spin up a Build 42 server, keep any Build 41 server intact, and avoid common multiplayer pitfalls. If you would rather not maintain two SteamCMD installs by hand, a managed Project Zomboid dedicated server installs Build 42 for you without touching the command line.
Important: Build 41 and Build 42 saves are not compatible, so a Build 41 world needs its own server on the Build 41 legacy branch rather than an upgrade.
Planning Checklist
| Task | Reason |
|---|---|
| Clone a new server directory | Keep Build 41 and Build 42 separated |
| Backup saves and configs | Build 42 saves cannot downgrade |
| Review mods | Many mods are not Build 42 ready |
| Match client branch | Every player must be on the same build as the server |
Step 1: Install Build 42 with SteamCMD
Build 42 is on the public branch, so no beta flag is needed. Example:
steamcmd +login anonymous +force_install_dir /opt/pz-b42 +app_update 380870 validate +quitIf you use a hosting panel, the stable option already installs Build 42.
Step 2: Configure Server Settings
Server settings live in Zomboid/Server/ as servertest.ini (or your custom name). Common settings to adjust first:
ServerName=Build 42 Test
MaxPlayers=16
Public=false
Password=
PVP=false
WorkshopItems=
Mods=
Use a separate server name so players can clearly identify the Build 42 test environment.
Step 3: Review Mods Carefully
- Disable non-essential mods until Build 42 compatibility is confirmed.
- Keep
WorkshopItemsandModslists aligned. - Update mods before every server restart.
Step 4: Launch the Server
Use the standard start script for your platform, but point it to the Build 42 install and server name. Example (Linux):
./start-server.sh -servername "servertest"On Windows, launch StartServer64.bat and select the same server name.
Step 5: Keep Clients Synced
Every player needs the same build as the server. A client that has not opted into any beta is already on Build 42; a client still on the Build 41 legacy beta, or on Pre-Release while the server is on public, will get a version mismatch error when connecting.
Troubleshooting
Server starts but players cannot join
Confirm the server and the clients are on the same build. Re-run SteamCMD updates if needed.
Mods cause startup crashes
Disable mods, start the server once, then re-enable mods one at a time.
Save file errors
Start a fresh Build 42 world. Build 41 saves will not load correctly.
Related Guides
- Playing Build 42, and what the Unstable branch was for
- Build 42 feature overview
- Complete server settings
- Enable whitelist and access control
Need a reliable test environment? Host your Project Zomboid server with Supercraft and swap branches in minutes.