Abiotic Factor Server Not Showing or Can't Connect (Fixes)

If your Abiotic Factor dedicated server is not in the server browser or friends cannot connect, the usual causes are: ports 7777 (game) and 27015 (query) are not reachable, the server or the players are on a different build, the list has not caught up yet or a filter hides it, the password is wrong, or a launch option like -LANOnly or -UseLocalIPs is limiting it. Direct Connect with the server's address skips the browser entirely and tells you whether the server itself is reachable, so try that first.

Start here: Direct Connect

The server browser depends on Steam's server list, which can be slow and sometimes misses servers. Direct Connect does not. Have a friend use Direct Connect with your server's public IP and game port, for example 203.0.113.25:7777.

• Direct Connect works, browser does not: the server is fine. The problem is the query port, a filter, or the list delay. Go to causes 2 and 3.
• Direct Connect fails too: the server is not reachable or refuses them. Go to causes 1, 4 and 5.

Cause 1: the game port is not open

The official quickstart starts the server with:

AbioticFactorServer-Win64-Shipping.exe -log -newconsole -PORT=7777 -QueryPort=27015 -ServerPassword=YourPassword -SteamServerName="Night Shift Crew"

The -PORT is where players connect. For a home hosted server, forward it on your router to the PC running the server, and allow AbioticFactorServer-Win64-Shipping.exe through Windows Defender Firewall on private and public networks. The official guide lists ports 7777 and 27015 as the ones to forward. Many people open them for both UDP and TCP to rule out the protocol as a cause.

If the forward looks right but the port is still closed from outside, check for double NAT (a provider modem that is also a router in front of yours) and carrier grade NAT, where no forward can work. The test is in how to tell if you are behind CGNAT, and the router steps are in our port forwarding guide.

Cause 2: the query port

-QueryPort is what Steam uses to advertise the server in the browser. The official docs call it not fully required but recommended. A server whose game port works but whose query port is blocked can be joined by Direct Connect and never shows in the list. Forward the query port too, and make sure no other program on the machine uses 27015, which is a popular port for Steam game servers. If you run a second server, give it different ports. Players in the Steam discussions have also reported that moving the query port to another number fixed a server that would not list.

Cause 3: the list is slow or filtered

• New servers can take a few minutes to appear after they start. Wait, then refresh.
• The list is long. Search a distinctive part of your server name instead of scrolling, and use a name nobody else uses.
• Check the browser filters. Dedicated servers and password protected servers can be filtered out, and every server starts with a password unless you remove it.
• Restarting the server takes it out of the list for a while again.

Cause 4: version mismatch

Abiotic Factor updates regularly. Players' clients update through Steam, and a server still on the old build refuses them with a version mismatch, or never shows in their list. Update the server with SteamCMD (the dedicated server app ID is 2857200), or keep auto update on so it pulls the new build on restart, and restart once Steam has the update. If a player has opted into a beta branch, they need to switch back to match the server.

Cause 5: password and launch options

• Password: -ServerPassword sets it. A quote or a space in the wrong place in the launch line changes the password silently. Keep it to letters and numbers.
• -LANOnly: makes the server only discoverable on the local network. Remove it for an internet server.
• -UseLocalIPs: binds to local addresses for troubleshooting. The official docs warn it can break joining from the internet, so remove it if friends cannot join.
• -MultiHome: binds to one IP. A wrong address here makes the server unreachable.
• Do not use -NOSTEAM. The official docs say not to, and it stops the server from working with Steam.

Cause 6: the Steam API failed to start

If the console shows Steam Dedicated Server API failed to initialize, the server cannot register with Steam at all, so it will never list. Make sure the full server files are installed through SteamCMD, that nothing else holds the same ports, and restart. On a home PC, close other running dedicated servers that use the same query port.

When one player cannot join

If everyone else gets in, the problem is on that player's side. Have them verify their game files in Steam (right click Abiotic Factor, Properties, Installed Files, Verify integrity), restart Steam, turn off any VPN and check that their antivirus is not blocking the game. Also make sure they are on the default branch.

The easy option

Causes 1, 2 and 6 are what home hosting looks like. A GamezServers Abiotic Factor server has its own address with the game and query ports open, auto update on, and the name, password and player cap as fields in the control panel. Friends can use Direct Connect with the address from the panel the moment the console shows the server is up, and the facility keeps running when you log off. Our guide to hosting an Abiotic Factor server covers the rest of the setup, and the sandbox settings guide covers tuning the run.

FAQ

Why is my Abiotic Factor server not in the server browser?

Usually the query port (27015 by default) is not reachable, a filter is hiding it, or the list has not caught up. Try Direct Connect, forward the query port, and search by name.

What ports does an Abiotic Factor server use?

The game port, 7777 by default, and the query port, 27015 by default. Both are set on the launch line with -PORT and -QueryPort.

How do I connect to an Abiotic Factor server by IP?

Use Direct Connect in the join menu and enter the server's IP and game port, such as 203.0.113.25:7777, then the password.

Why do players get a version mismatch?

The server and the players are on different builds. Update the server through SteamCMD or with auto update on and restart it.

Can I remove the password from my Abiotic Factor server?

Yes. Leave -ServerPassword empty, or clear the password field in your panel, and restart. Anyone who finds it can then join.