TerraTech Worlds Can't Connect to Dedicated Server: Fixes

When TerraTech Worlds will not connect to a dedicated server, check four things in order: the server and every player are on the same build and the same branch (stable or unstable), the Host Address is typed as IP:port with the server's real port, that port is open as UDP, and the password uses only letters, numbers, dashes and underscores. Most failures right after a patch are the first one. Here is how to work through each.

How joining works

TerraTech Worlds has no server browser for dedicated servers. Players open the multiplayer menu, choose Join Dedicated Server, type an address into Host Address and press Launch. The game then connects straight to that address over UDP. That makes it simple, but it also means a typo, a closed port or a version gap all look the same from the player's side: it just does not connect.

Fix 1: Same build, same branch

TerraTech Worlds is in Early Access with a steady stream of updates: 0.6.x through 2025, 0.7 in February 2026 and 0.8 (adding the water planet Tyr) in April 2026, with hotfixes between. Payload Studios also runs an unstable branch where updates land first.

Players update automatically on Steam. A dedicated server does not, unless it is set to update when it starts. So after any patch:

• Update the server (SteamCMD app 2533070, then restart), or just restart if it auto updates.
• Make sure everyone, server included, is on the same branch. One friend opted into unstable cannot join a stable server, and the other way round.
• Fully restart the game after an update before trying again.

The developers warn to back up saves before switching to the unstable branch. Do that on the server too.

Fix 2: Type the Host Address correctly

The Host Address takes the server's public IP and its port, for example:

203.0.113.10:7777

Common mistakes:

• Leaving off the port when the server does not use the default.
• Using a local 192.168.x.x address from outside the host's home network.
• An old IP. Home connections change IP now and then, so a saved address can go stale.
• Spaces before or after the address when pasting.

If the server runs at home, check the current public IP on any "what is my IP" site from that network.

Fix 3: Open the port as UDP

The server uses one port, set as Port in dedicated_server_config.json. It must be forwarded as UDP. A TCP only rule is the classic reason friends time out while the host can connect locally.

1. Forward the port as UDP on the router to the machine running the server.
2. Add an inbound UDP rule in Windows Defender Firewall for the server.
3. If the server is on a VPS, open it in the provider's firewall as well.

Our port forwarding guide covers the router side, including how to spot carrier grade NAT, where forwarding cannot work.

Fix 4: Check the password

Set the password in the config's Password field. Keep it to letters, numbers, dashes and underscores: spaces and symbols cause failed joins that look like connection errors. After changing it, restart the server so it loads, and make sure players type it exactly.

Fix 5: The server crashes when someone joins

If the server process stops the moment a player connects, read the last lines of its log and check recent patch notes. TerraTech Worlds has had joining crashes tied to specific builds before. One unstable build in late 2025 shipped with joining a dedicated server listed as a known crash, fixed in the next unstable release. A crash for every client when a Delivery Rocket was launched in multiplayer was fixed in a 0.7 hotfix in March 2026. If you are on a build with a known issue, update past it, or stay on stable rather than unstable for a group server.

Fix 6: Broken config file

dedicated_server_config.json must be valid JSON. A missing comma, an extra comma after the last value or a stray quote stops the server from reading it, which can leave it on defaults or not starting at all. Compare against this shape:

{
  "Port": 7777,
  "Password": "our_crew",
  "SlotCount": 6
}

Fix 7: The server is full

SlotCount is the cap. The developers recommend 6 for dedicated servers. If a seventh friend cannot join a server set to 6, that is the reason, not a network fault.

Quick diagnosis

A server that stays in step

On a TerraTech Worlds server from GamezServers, the port is open and the address is fixed, so fixes 2 and 3 come down to copying the address from the panel. Auto Update pulls the newest build every time the server starts, so a restart after a patch keeps it in step with players. Password and Max Players (up to 6) are panel settings, the server runs the Windows build, and one click backups protect your bases before a big update. For setting one up yourself, see how to host a TerraTech Worlds server.

FAQ

How do I join a TerraTech Worlds dedicated server?

Open the multiplayer menu, choose Join Dedicated Server, type the server's IP:port into Host Address and press Launch.

Why does TerraTech Worlds say version mismatch?

The server and your game are on different builds or branches. Update the server and make sure everyone is on the same stable or unstable branch.

What port does a TerraTech Worlds server use?

One UDP port, the Port value in dedicated_server_config.json. It must be forwarded as UDP.

Is there a server browser for TerraTech Worlds dedicated servers?

No. Players join by typing the address into Host Address.