Fixes · 7 min read
Project Zomboid server not showing, or friends can't join?
Not in the server list, "The server is not responding", a version or mod mismatch, a wrong password: what each Project Zomboid join error means.
Last checked
Short answer
Public on, so friends should add it by address instead: Join, Favorites, Add Server, then the address and port. If that still fails, check the server has finished starting, both UDP ports reach it, and everyone is on the same build and mod list as the server. Then check the password and account settings. Work down this list in order.What the message on screen means
These are the game's own words in Build 42, and the check below that deals with each.
| What players see | Usual cause | Fix |
|---|---|---|
| The server isn't in the list | Usual causePublic is off, as it is by default | FixCheck 2 |
| “The server is not responding.” or “Connection Failed” | Usual causeStill starting, a wrong address or port, or a port that doesn't reach it | FixChecks 1 to 3 |
| “Server version (…) does not match the client (…).” | Usual causeA different build or branch | FixCheck 4 |
| “Workshop item version is different than the server's” or “Mod … is not installed” | Usual causeMods out of step | FixCheck 5 |
| “Wrong server password given” | Usual causeThe join password | FixCheck 6 |
| “Wrong username or password given” or “Unknown account username given” | Usual causeThe player's own account on the server | FixCheck 6 |
| “The server is full” | Usual causeThe player cap | FixCheck 6 |
| “You have been kicked because your game files do not match the server's.” | Usual causeThe game-files check | FixCheck 7 |
| “Your ping is too high for connection to this server.” | Usual causeA ping limit is set | FixCheck 7 |
1. It's still starting
Nobody can join until the server console prints *** SERVER STARTED ****. That took about a minute in our tests, longer the first time and whenever it downloads an update or Workshop mods first.
On our servers, the panel marks the server Running once that line appears; it took a minute or two in our tests (92 to 99 seconds). Until then the status reads Starting; wait for Running before anyone tries to join.
2. You're looking for it in the list
A Zomboid server only appears in the game's Internet list if it's set to public, and that's off by default, on ours too. Friends don't need the list. In Project Zomboid, go to Join → Favorites → Add Server. Put the address in IP/Domain, the port in Port, and the join password in Server Password if there is one (see 6). Save, select the server and join.
The game also asks for an Account Username and Account Password: that's the player's own account on the server, anything they like the first time, and not the same thing as the join password.
On a home server the port is 16261 unless you changed DefaultPort. On ours, the Join address box in the panel shows the address, a colon, then the port, and its copy button copies all of it. Split it across the game's two boxes: everything before the colon goes in IP/Domain, the number after it in Port. Don't assume 16261: each of our servers gets its own port.
You want it in the list after all
At home, set Public=true in servertest.ini and restart; the servertest.ini generator lists it with every other setting. On ours, open Game → All settings → Server settings and switch on Show in server browser, under Server listing, then save and restart. The name it lists under is Server name, which you change in All settings → Startup settings, under Server.
That switch is for the game's own list. The game's file notes that Steam-enabled servers, which ours are, always show in Steam's server browser whatever it says. Either way, anyone who finds the server can try to join it, so set a join password (see 6) unless that's what you want.
3. The ports don't reach the server
Zomboid uses two UDP ports in a row, 16261 and 16262 by default. Players only type the first, but the server needs both.
On your own PC, forward both UDP ports to the server PC, give that PC a fixed address on your home network, and let the server through its firewall. The server tries UPnP by itself (UPnP=true), but not every router allows it, so don't rely on it. Players on the same home network as the server should put the server PC's local address in the optional Local IP box when they add it. The full setup is in the guide to hosting a Project Zomboid server.
On our servers, both ports are open already. To rule out the server itself, press Run the checks under Can players reach it? on the server's Overview tab. The game port line sends the server a Steam query: Works means it answered from the internet. No answer usually means it hasn't finished starting (see 1). The second port can't be tested from outside and shows as Not tested. If the game port works but a friend still can't connect, the problem is likely on their side: a router, firewall or VPN.
4. The game updated, or someone's on another branch
“Server version (…) does not match the client (…)” means exactly that. Zomboid patches often (42.22.2 came out on 9 November 2026), and Steam updates players' games by default. Build 42 has been the default branch since 29 July 2026; Build 41 lives on the legacy41 branch, and test builds on pre-release, which replaced unstable.
On your own PC, stop the server and run the SteamCMD install again, with -beta legacy41 or -beta pre-release if your group plays one of those.
On our servers, the server updates when it starts (Update on start, in All settings → Startup settings, on by default), so after a patch, restart it to bring it up to the build your players now have. If your group plays another branch, open Settings → Game version, type the branch name, such as legacy41, and press Change version. The panel reinstalls the game on that branch. A world saved on a newer build may not load on an older one, so download your world first.
Players switch branch in Steam: right-click the game, then Properties, then Game Versions & Betas.
5. The mods don't match
Players download the server's Workshop mods automatically when they connect. “Workshop item version is different than the server's” means one side is behind: the game itself suggests restarting the server if it's the server, or restarting Steam if it's the player. After a game update, some mods may not work until their authors update them, so if players can't get in after a patch, check each mod's Workshop page first.
A server's mods are two lists that must agree: Workshop item IDs (the number at the end of the mod's Workshop page address) and mod IDs (the id= line in the mod's mod.info file). At home they are WorkshopItems= and Mods= in servertest.ini. On ours they are Workshop item IDs and Mod IDs in All settings → Server settings (switch on Advanced to see them). A mod removed from the Workshop can't be downloaded any more, by the server or by players.
6. The password, account or player cap keeps them out
“Wrong server password given” is the join password, typed in Server Password when adding the server. At home it's Password= in servertest.ini. On ours, set it in Join password on the Game page, under Players and bases: letters, numbers, dots, dashes and underscores, up to 32 characters. We write it into the server's file at every start, so a password typed straight into the file is replaced.
“Wrong username or password given” is about the player's own account. The first time a name joins, the server makes an account with the password they typed; after that, the same name needs the same password. Use the account name and password they used before, or a new name. “Unknown account username given” means the server doesn't let new players make accounts: Open=true at home, or Open to new players on ours (All settings, under Joining), lets them in. It's on by default.
“The server is full” means it's reached its cap, which doesn't count admins. The game's own default is 32; ours start at 10. Raise MaxPlayers at home, or Maximum players on our Game page under Players and bases, and restart.
If your group used to play this world through the in-game Host button and a player arrives stuck in a void, the game's wiki suggests a new profile: change the account name in that server's entry (player becomes player_1), save, and join again.
7. The server kicks them as they connect
“You have been kicked because your game files do not match the server's” comes from the game-files check, DoLuaChecksum (Check game files on ours, in All settings with Advanced on). It's on by default and should stay on, because it keeps out tampered files. First make sure the player's build and mods match the server's (checks 4 and 5); in Steam, verifying the player's game files can fix a damaged install. The game's wiki warns of a bug that flags false positives on Linux servers, and ours run Linux, so if everything matches and players are still kicked, send us the console before you switch it off.
“Your ping is too high for connection to this server” means a ping limit is set: PingLimit in the file, Ping limit under Joining on ours. 0 turns it off, and that's the default.
Still stuck?
On your own PC, read the server console from the moment the player tries to join: it usually names the reason they were refused.
On our Project Zomboid servers, press the copy icon in the console (Copy the last 200 lines), then Contact a human on your server's page and paste them into your message, with what the player sees on screen. A person reads it, not a bot.
Game facts checked against Project Zomboid 42.22.2.