Update a Terraria serverKeeping versions in sync - the most common reason for locked-out servers

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

Why the update is urgent

Steam updates Terraria automatically when it starts. Your server does not - it stays on the version it was last started with.

As soon as the versions drift apart, Terraria refuses the connection and names the version in plain text. To players, it looks like a server error, but it is not one - see connection problems.

Unlike games with a more tolerant protocol, there is no leeway here: even a small difference is enough. After a Terraria update, you should therefore be the first to test whether you can still get onto your server.

The right order

1. Inform players and stop the server during a quiet phase.
2. Back up. Download the world file and the serverconfig.txt - see create backups.
3. Switch the server version and let the update run through.
4. Check that the serverconfig.txt is still in place. Depending on the procedure, a reinstallation can overwrite configuration files.
5. Start the server and watch the console.
6. Connect yourself and check whether the world has loaded completely.

Step 4 is the one people overlook. If an empty world suddenly runs after the update or the port is no longer right, the configuration has usually been reset - then enter world=, port= and password= again. The values are explained in serverconfig.txt explained.

What happens to the world

With a normal version change, the world is preserved and raised to the new format on the first start. Still, you should know two points:

• The conversion only goes forward. A world that has been started once under the new version can no longer be played reliably under the old one. The way back is the backup from before.
• New content often only appears in unexplored areas. New ores, structures or biomes do not show up retroactively in areas that have already been generated.

If you want to see the new content in full, start a new world - and keep the old one as a backed-up file. How to switch between worlds is explained in upload a world.

The special case of tModLoader

On a modded server, there is a chain that has to fit completely:

1. The Terraria version that tModLoader is based on.
2. The tModLoader version itself - it has to match on server and client.
3. The mods, which have to match the tModLoader version.

That has an uncomfortable consequence: you should not update a tModLoader server reflexively. When a new Terraria comes out, tModLoader and then the mods need time to catch up. Anyone who updates immediately may be left without a working modpack for weeks.

The proven order: wait until the mods you use are available for the new version - only then switch the server and players over together. Details in tModLoader & Calamity.

And with TShock?

TShock is also tied to a specific Terraria version. After a Terraria update, a matching TShock version is needed before the server runs again.

The difference from tModLoader: nothing changes for your players - they use the normal Terraria client. Only you as the operator have to wait for the matching version. Before the update, also back up the TShock configuration including user accounts and regions, see set up TShock.

Frequently asked questions