How to Install BepInEx Mods on a Valheim Dedicated Server

Which mods need to be where

Every Valheim mod falls into one of three groups, and its Thunderstore or Nexus page should say which:

• Server-side only. Runs on the server and players need nothing. These are the safest option, especially for a crossplay server.
• Client-side only. Cosmetic or interface mods that each player installs for themselves. The server does not need them.
• Both sides. Content and gameplay mods. The server and every player need the same mod at the same version, and some enforce a strict match and kick clients that differ.

Step 1: install BepInExPack on the server

Use the BepInExPack_Valheim package by denikson on Thunderstore. It is BepInEx 5 with Valheim-specific changes (a preconfigured BepInEx.cfg, start scripts for Linux, and a patched preloader). A clean, unmodified server folder gives the fewest surprises.

1. Download the pack

   Take the manual download from the BepInExPack_Valheim page on Thunderstore and extract it somewhere outside the server folder.

2. Copy it into the server folder

   Move the contents of the BepInExPack_Valheim folder into the folder that holds valheim_server.exe. You should see BepInEx, winhttp.dll and doorstop_config.ini next to the executable. Host guides also list a doorstop_libs folder.

3. Linux only: make the start script executable

   Run the command below, edit the launch parameters inside the script as you would Valheim's own start script, then launch it.

   Copy

   chmod u+x start_server_bepinex.sh

4. Start once and confirm

   On first run BepInEx creates BepInEx/config and BepInEx/LogOutput.log. Seeing BepInEx messages in the console or log confirms the loader attached.

If you run Valheim on a hosted server, check what the host already installs. Hosting with ChicagoServers? The Valheim server hosting page lists what is included, such as a one-click BepInEx installer, free server backups and SFTP file access.

Step 2: add mods one at a time

1. Stop the server.
2. Download the mod from Thunderstore (or Nexus). Read its description for required dependencies and for whether it is server-side, client-side or both.
3. Copy its .dll files into BepInEx/plugins. Subfolders are fine, and a mod's whole plugins folder can be copied as is.
4. Install any dependencies first. A library called Jotunn is the one people most often forget.
5. Start the server and read BepInEx/LogOutput.log for the plugin list and any errors.
6. Add the next mod only when the first one loads cleanly.

After a mod's first run it writes a config file into BepInEx/config, one per mod. Edit it, save and restart. Some mods push their configuration from the server to players; the mod's page says which. For mods that do not, send the same config file to your players.

Step 3: make players match the server

Players install the same BepInExPack version and the same mods. The easiest route is a mod manager such as r2modman, Thunderstore Mod Manager or Gale: create a profile, install the same mods at the same versions, and launch from the manager. Exporting the profile as a code lets the whole group import an identical set. On Linux clients, the Thunderstore page tells you to set the Steam launch option to ./start_game_bepinex.sh %command%.

Keep a short list in your Discord of exactly which mods and versions the server runs. Valheim does not sync mods itself, so this list is your only source of truth.

Common failures and what they usually mean

Frequently asked questions