This guide assumes you see an error referencing a file or module named steamworks.mfx (or similar) when launching or using a game or mod that integrates Steamworks. Follow the steps below from quickest to more advanced.
Additional resources
archive (running the game directly from inside a zip folder often causes this error). 5. Run as Administrator steamworks.mfx error
Or a variation like:
Solution 6: Re-register the Steamworks.mfx file Troubleshooting guide: "steamworks