Updating to Valheim 1.0

1. Stop the server cleanly and complete a backup of the world and configuration before upgrading. Back up the entire world save directory, including hidden files and every chunk, rather than selecting individual extensions.
2. Check BepInEx and every installed mod against the target release before updating a modded world. Valheim does not guarantee mod compatibility.
3. Update the dedicated server and player clients to compatible releases, then verify startup, joining and saving before resuming play.
4. Existing worlds can continue in 1.0. New biome content generates properly in unexplored areas; a fresh world is optional.

ImportantTested release: Valheim 1.0.15 on September 21, 2026. Check the version shown in your own server console and confirm mod compatibility before updating.

Start parameters

1. -name sets the name shown in the browser.
2. -world sets the save to load or create.
3. -password must be at least 5 characters and cannot be contained in the server name.
4. -public 1 lists the server in the community browser; -public 0 is friends/direct only.
5. Add -crossplay to enable PlayStation/Xbox/PC crossplay through the PlayFab network.

ImportantA public server (-public 1) must have a valid password (5+ characters, not part of the name) or it will refuse to advertise.

Admins and the world files

1. Add trusted players to adminlist.txt using their Steam ID, one per line.
2. Stop the server before copying saves. Older saves use a matched .db and .fwl pair; the 1.0.15 build tested by Runic uses a world subfolder with .chunk, .chunks, .db2, .fwl2 and .ok files. Back up or move the complete world folder inside worlds_local, preserving its structure.