Install one mod with a rollback path
- Step 1: Close Valheim, make a dated copy of the world and character saves, install the documented loader in the game folder, and create a separate test profile.
- Step 2: Put the mod dependency and plugin files in the paths named by the mod documentation, launch the test profile once, and inspect the loader/plugin log.
- Step 3: Add only one plugin per test, save and reload the profile, then remove the last plugin and retest the clean profile when loading or behavior fails; a successful test has a clean launch, the expected plugin path, and an unchanged copied save.
- Step 4: Launch once, inspect the log and expected plugin/config path, then stop if the clean profile no longer loads.
Valheim has no official Mod support, so install third-party Mods only after backing up the world and character. For the common BepInEx route, use the game’s local installation folder, copy the loader files there, and put a plugin DLL in BepInEx\plugins and its configuration in BepInEx\config. Steam users can reach the folder through Library → Valheim → Manage → Browse local files. Install the exact loader and dependency versions named by the Mod release; do not copy files from an older guide into a 1.0 profile.
A mod installation has five separate parts: the loader, dependencies, plugin files, configuration, and save data. Keep those parts visible so a failed launch can be rolled back without guessing which file changed the world.
- Copy the world and character saves before installing the first loader or plugin.
- Launch after one change and inspect the expected plugin and configuration path.
- When the result fails, remove the last change first and return to the clean profile before editing several files.
Roll back safely
- Remove the last plugin and retest the clean profile.
- Compare the loader and game versions before changing configs.
- Keep the backup outside the active save folder.