Server online, but a player can't get in? B42 join failures are almost always one of the six below — work down the list in order, it's sorted by how often each one is the answer.
1. Game build mismatch (the big one)
Everyone must be on Build 42 — the build your server runs. A player still on the B41 legacy branch (set months ago in Steam and forgotten) will fail to join or see version errors.
Fix: in Steam → Project Zomboid → Properties → Betas, select the default/B42 branch, let it update, retry. Have them check the game's main-menu version string matches your server's build.
2. Stale or wrong-build client mods
If your server runs Workshop mods, joining clients auto-download them — but a client already subscribed to a mod's B41 edition, or holding a stale download, errors on join or crashes on the loading screen.
Fix: the affected player unsubscribes the mod(s) in the Workshop, verifies game files, restarts Steam, rejoins (the download happens again, clean). If everyone suddenly can't join after you changed the mod list, the problem is the server list itself — see Installing Workshop Mods.
3. Wrong password — or wrong account password
Two different passwords trip people:
- The server password (if you set one in Settings) — needed by everyone.
- Each player's personal account password, chosen on their first join. Typing a different one later reads as a failed login, not "wrong password for the server".
Fix: confirm which prompt is failing. Forgotten account password: an admin can reset it in-game, or ask us via ticket.
4. The server is still booting
Between "Start" and SERVER STARTED in the console, joins time out — and B42 first boots (or boots after adding big mods) can take several minutes while the world generates or Workshop items download.
Fix: watch the console on the Overview tab; invite people once SERVER STARTED appears.
5. Joining the wrong way
Console players don't exist for PZ — everyone is on PC — but the in-game browser can still mislead: a non-public server never appears in the Internet list, and search filters hide servers unexpectedly.
Fix: skip the browser entirely: Favorites → Add to favorites with the exact host and port from your connection card. If favorites works and the browser doesn't, it was only visibility, not connectivity.
6. One player, weird symptoms
If exactly one player rubber-bands, disconnects, or freezes while everyone else is fine, it's their side: Wi-Fi, a VPN, distance to the server's region, or an overloaded PC.
Fix: wired connection, VPN off, verify files. If they're on another continent, physics applies — their ping to your server's region is what it is.
Still stuck?
Open a ticket from your dashboard with: the player's exact error text, whether anyone can join, and whether the mod list changed recently. Those three answers usually let us solve it in one reply.