Are you running mods?


I think you can back up progress, if you use steam cloud it may save it there as well so you should not lose any progress. Even using steam cloud I would back up the files just in case before doing a reinstall.

Have you tried to verify local files? Library - right click game name - properties - local files - verify.

Also I assume you checked the sound mixer to see if Valhiem is muted there. Could be your cat stumbled across your keyboard turning you into Dexter Douglas and muted the game randomly.