Terraria: connection to the server failedVersion, server variant and the typical join errors

Published on August 9, 2026 · last updated on November 3, 2026

Classify first, then search

Before you change anything, assign the error to one of three groups - that saves half the search:

• Nothing happens at all. The connection attempt goes nowhere or aborts without a message. Then the address is wrong, or the server is not running.
• Terraria names a reason. Version, mods, password. Then the connection was technically established and the server deliberately refused - which proves the address is correct.
• It works for some, not for others. Then it is not the server but the client of the person affected: a different game version, different mods, the wrong server type.

The third point is the most valuable test of all. If at least one person gets in, you do not need to check anything on the server - address, port and server status are fine, and the cause lies with the individual player. If nobody gets in, first take a look at the server console in the web interface: if there is no startup message with the world name, the server did not come up cleanly at all, and the cause lies before the network - for example a world that was not found, see upload a world.

Version mismatch: the most common case

Terraria allows no difference between client and server. If the server runs a different game version, the connection is refused with a note about the version.

• After a Terraria update, Steam updates the client automatically - the server has to catch up.
• With tModLoader, the tModLoader version also has to match on both sides, not just the Terraria version underneath.
• Conversely, a client can be too new - then switching to the matching branch in Steam helps.

You set the server version in the web interface; for modded servers, this is described in tModLoader & Calamity.

Wrong server type

Terraria has three server variants, and they are not compatible with each other:

• Vanilla - the standard server without extensions.
• TShock - extends Vanilla with management, regions and plugins. To players, it behaves like a Vanilla server.
• tModLoader - for real mods. A normal Terraria client can not join here; it takes the tModLoader client.

The classic: the server runs on tModLoader, but the other players start normal Terraria. Then no address will help - they have to start tModLoader. Conversely, a tModLoader client cannot get onto a Vanilla server.

Mods do not match

On a tModLoader server, players have to have the same mods enabled as the server. If one is missing or has a different version, the join is refused.

tModLoader usually offers to download missing mods when joining. That takes time the first time and fails if a mod is no longer publicly available. If in doubt, compare the enabled.json file on the server with the client's mod list - see install tModLoader & Calamity.

Address, port and password

In Terraria, you join via Multiplayer > Join via IP. The game then asks for address, port and password one after the other - three separate inputs:

1. Enter the IP - without the port, which comes in the next step.
2. Enter the port. The default is 7777; what counts is the port from the web interface.
3. Enter the password if one is set in the serverconfig.txt - otherwise leave it empty.

A common mistake is writing IP and port together in the first field. The way in detail is described in join a Terraria server.

Refused or kicked

If the connection is established and ends immediately, the server is deciding deliberately:

• Full server - maxplayers in the serverconfig.txt has been reached.
• Ban - on TShock servers, it can be checked and lifted via the management tools.
• Wrong password - Terraria does not always report this clearly.

On TShock servers, a permission rule can also apply - the management is described in set up TShock.

Dropouts during play

A different case from a failed join: the connection is established but keeps dropping or stuttering. No error message helps here, but the timing does - the pattern reveals the cause more reliably than any test.

• Always in the same place in the world. Typical of tight memory with large content mods: the server hangs when entering new areas or when changing worlds. A single broken mod behaves differently, namely regardless of location - the distinction is described in tModLoader & Calamity.
• After a big building project. Flowing liquids are calculated permanently and load the server even when nobody is nearby. The console command settle ends that, see server commands.
• Only for one person, at changing times. Then it is their connection. Wi-Fi and mobile connections are the usual suspects; a test via cable clarifies this faster than any server analysis.

The server itself is the cause less often than people suspect. The connection is located in Frankfurt am Main and secured with DDoS protection of up to 250 Gbit/⁠s - an attack as an explanation is correspondingly unlikely. If a problem remains reproducible and fits none of the patterns above, back up the world file as a precaution before you tinker further with configuration or mods. Backups are self-service via WebFTP and SFTP; the process is described in create backups.

Frequently asked questions