SuperTuxKart Server Not Showing Online or Can't Connect (Fixes)

A SuperTuxKart server is missing from Global networking for one of three reasons: it was started with --lan-server (LAN servers never go on the global list), it was started with --wan-server but has no saved STK online login, or the private ones are hidden because the list is set to Public servers. If players can see it but cannot get in, the cause is almost always a closed UDP port 2759, a version or track mismatch (Connection refused: Game data is incompatible.), or a wrong address. Every server, listed or not, can be joined with Online > Enter server address and ip:port.

Work down the sections in order. The server log and the exact message the player sees point to the right one quickly.

Quick diagnosis

1. It is a LAN server, so it will never be listed

The start command decides this, not a menu. A server started with:

supertuxkart --server-config=config.xml --lan-server=MyServer --network-console

sets wan-server to false no matter what the XML says. It does not register with the STK online service, so it never appears in Global networking. It only shows under Local networking for players on the same network, found through discovery port UDP 2757.

That is not a fault. The official NETWORKING.md says a LAN server can be joined over the internet by typing its public address with the port into Enter server address. Many groups prefer it: no account needed, no strangers.

This is also how a GamezServers SuperTuxKart server runs: as a LAN server with its own address, joined by address, kept off the public list on purpose. If you are a customer and wondering why your lobby is not in the global list, this is the reason, and the fix is to share the address.

2. A WAN server without a saved login

To be listed, the server must be started with --wan-server=Name (or wan-server true in the XML) and have a saved STK online account. On the server machine, run once:

supertuxkart --init-user --login=your_name --password=your_password

and look for Done saving user, leaving. Then start the server again. Messages to look for in the server log:

• Server <number> is now online. The server registered and should appear within a refresh or two.
• No saved online player session to create or connect to a wan server. The login step was skipped or ran as a different system user. Run --init-user as the same user that runs the server.
• Timed out trying to login saved session, check connection to stk addons or rerun --init-user. The server cannot reach the STK online service, or the saved session expired. Check outbound internet on the server and rerun --init-user.
• You don't have permission to host a ranked server. ranked is true in the XML. Set it to false; ranked servers need approval from the STK team.

The STK team also removes listed servers meant to run 24/7 that are not reachable directly, so an always on WAN server needs its port forwarded rather than relying on NAT punching.

3. The player is not looking in the right place

On the player side, a few settings hide servers:

1. Global networking needs a signed in account. Without one the game shows You must be logged in to play Global networking. Click your username above. Create a free account at online.supertuxkart.net or use Enter server address instead.
2. Connect to the Internet must be on. Otherwise the game says You can not play online without internet access. Turn on Connect to the Internet in the options.
3. Public vs private servers. The server list has a dropdown with Public servers and Private servers. A server with private-server-password set only shows under Private servers.
4. Refresh. A new WAN server can take a moment to show after is now online. Use the reload button.

4. The port is not reachable

SuperTuxKart servers use UDP 2759 by default. Connections that hang and end with Server connection timed out. or Cannot connect to server ... mean packets are not arriving.

• Firewall on the server. On Linux with ufw: sudo ufw allow 2759/udp. On Windows, allow supertuxkart.exe through Windows Defender Firewall for UDP.
• Router. Forward UDP 2759 to the server's local IP. A LAN server does no NAT traversal at all, so without a forward nobody outside your home can join. Router specific steps are in how to port forward a game server.
• CGNAT. If your router's WAN IP is not your public IP, forwarding cannot work; see hosting without port forwarding.
• The server moved port. If 2759 was taken, STK binds a random port instead. Check the startup log for the port actually in use and give players that number.
• IPv6. The server list screen warns No IPv4 detected, you may not be able to join any servers. or the IPv6 version if a player's connection lacks one. A player on an IPv6 only mobile network may need Wi-Fi to reach an IPv4 server.

5. Version and game data mismatch

Connection refused: Game data is incompatible. covers two different problems.

Network version. Every 1.x release from 1.0 to 1.5 uses the same server protocol version (6), so a 1.4 player can usually join a 1.5 server. Very old 0.9.x builds cannot. If the server log shows Player refused: wrong server version in verbose logging, the player needs to update. Linux distribution packages are often a release behind, so compare the version on the main menu with the server's.

Missing official tracks or karts. The server compares how many official tracks and karts the client has against official-tracks-threshold (default 0.7) and official-karts-threshold (default 1). The Android version leaves out some official tracks, so if you raised the track threshold to 1, Android players are refused with this same message. Put it back to 0.7. Settings like these are covered in SuperTuxKart server config.xml explained.

Add-on tracks do not cause a refusal. The vote only offers tracks that the server and the players in the lobby have, so one player without an add-on keeps it out of the vote rather than being kicked.

6. Address, password, full or banned

Address format. In Enter server address, type the IP or host name, a colon, then the port: 203.0.113.25:2759. A space, a missing port when the server is not on 2759, or a typo gives Invalid server address: .... The dialog keeps a history list, so after one successful join players can pick it from there.

Password. Connection refused: Server password is incorrect. means private-server-password is set. Players enter it when asked, and it is case sensitive.

Full. Connection refused: Server is full. means server-max-players is reached. Raise it in the XML or with --max-players.

Banned. Connection refused: You are banned from the server. comes from a kickban in the network console or a ban table. Use listban in the console to check.

The easy route

If the goal is a private kart lobby for your friends rather than a spot in the public list, a hosted LAN server removes most of this page. A GamezServers SuperTuxKart server gets its own address within about a minute of paying, with no router or firewall to set up and always on DDoS protection. Name, mode, difficulty, max players and message of the day are in the panel, and players join with Enter server address. Setting one up yourself instead? Follow how to host a SuperTuxKart server.

FAQ

Why is my SuperTuxKart server not in the server list?

It is most likely a LAN server, which never appears in Global networking, or a WAN server without a saved login from --init-user. Players can still join any server with Enter server address.

Do players need an account to join my server?

Not for a LAN server joined by address. Browsing Global networking requires a signed in STK account.

Can a 1.4 player join a 1.5 server?

Usually yes, since the 1.x releases share network protocol version 6. If they get "Game data is incompatible", check the official track threshold or have them update.

What does "Server connection timed out" mean?

The player's game could not reach the server's UDP port. Open or forward UDP 2759, or the port the server log shows, and try again.

How do I find my server's address?

On a home server, it is your public IP plus the port. On a hosted server, it is shown in the control panel.