How to Restore a Corrupted Terraria World on a Server

To restore a corrupted Terraria world on a server, stop the server, open the worlds folder, rename the damaged <world>.wld out of the way, and rename <world>.wld.bak to <world>.wld. Terraria writes that .bak copy of the previous save every time it saves, so you usually lose only the time since the save before last. On tModLoader, do the same with the .twld and .twld.bak files so the modded data matches. Then start the server and check the world loads.

Signs the world file is damaged

• The server console shows the world failing to load, such as "Load failed!", and drops back to the world selection or exits.
• The server starts but makes a brand new world, because the configured file could not be read.
• The .wld file is 0 KB or much smaller than usual.
• Players get disconnected while the world is loading, and the console shows an error at the same moment.

The usual cause is the server being stopped while it was writing the world: a crash, a power cut, the window being closed, or the process being killed during an autosave.

Before anything else, check the cause is not simpler. A world saved by a newer version of Terraria will not load on an older server, which looks like corruption but is not. If you or a player recently opened the world on a newer game version, update the server first. The version mismatch guide covers that.

Where the world files are

If the server starts with -world pointing at a full path, or worldpath in serverconfig.txt, the world lives there instead. On a GamezServers server, open the Files tab and look in the worlds folder of your server type.

In that folder, each world has:

Step 1: Stop the server and copy everything

Stop the server. Download the whole worlds folder, every file, before renaming anything. If the backup is damaged too, you want the originals to try other options.

Step 2: Restore the vanilla world from .bak

1. Rename <world>.wld to <world>.wld.broken.
2. Copy <world>.wld.bak and rename the copy to <world>.wld.
3. Keep the original .bak as it is.

Step 3: tModLoader worlds need both halves

A tModLoader world is split in two. The .wld holds the vanilla world and the .twld holds everything mods added: modded tiles, items in chests, NPCs and mod world data. They must come from the same save.

1. Rename <world>.twld to <world>.twld.broken.
2. Copy <world>.twld.bak and rename the copy to <world>.twld.

Restoring only one of the two leaves modded blocks and items out of step with the world, which can look like a different kind of corruption. If the .twld.bak is missing, try loading with the restored .wld and the current .twld and check carefully before letting players in.

Step 4: Start and check

Start the server and watch the console until the world has loaded and the server is listening. Join and check the spawn area, a base and a chest or two. If it loads, let the group back in and tell them the world is back to the previous save.

If it still fails, the backup was saved during the same problem. Try the next step.

Step 5: Other copies to try

• Your own backups. Any copy of the worlds folder from a backup or an earlier download.
• The world on a player's PC. If the world started as someone's single player world and was uploaded, the original on their PC may be newer than you think. Check their Worlds folder, and Steam Cloud worlds inside the game's world menu.
• Older uploads. If you moved the world to a server once, the file you uploaded then still works as an older restore point.

The guides on uploading a Terraria world and moving a tModLoader world show where those copies live.

tModLoader: corruption that is really a missing mod

When a tModLoader world loads but modded items and blocks turn into "unloaded" placeholders, the world is not corrupted. A mod it used is missing or disabled on the server. tModLoader keeps that data safely as unloaded content until the mod is back. Re enable the mod, in the same version if you can, and the items return. Do not save over a world with important mods missing if you plan to bring them back.

Stop it happening again

• Shut down cleanly. Type exit in the server console, which saves and then stops. Closing the window or killing the process mid save is the main cause of damaged worlds.
• Keep your own backups. The .bak only holds one previous save. Copy the worlds folder before boss fights, updates and mod changes.
• Do not open the server's world in single player at the same time. Two copies saving over each other can lose progress.
• Watch memory on modded servers. Big tModLoader packs that run out of memory crash mid save. More in adding mods to a Terraria server.

On a GamezServers Terraria server, the stop button shuts the server down properly, one click backups cover the whole worlds folder, and the file manager makes the rename in Step 2 a minute's work. You can run vanilla, tModLoader or TShock and switch between them from the panel. For a world your group can count on, see the Terraria game page or tModLoader hosting.

FAQ

What is the .wld.bak file in Terraria?

It is the previous save of the world. Terraria keeps it next to the .wld so you can roll back one save if the current file is damaged.

How do I fix "Load failed" on a Terraria server?

Stop the server, rename the .wld out of the way and rename the .wld.bak to .wld. On tModLoader do the same for .twld. If the world came from a newer game version, update the server instead.

Will restoring the .bak lose progress?

Only what happened since the save before last, usually a few minutes to an hour depending on when the world last saved.

Why are my modded items showing as unloaded?

A mod the world used is missing or disabled on the server. Enable it again and the items come back.