This is the first time I've tried to run Jedi Knight from GOG (I still have CDs). I played through most of the first two levels before I realized there wasn't any music. I Googled the problem and ended up downloading this fix: https://www.gamepressure.com/download.asp?ID=78491 I tried all the things it said to do and none of them got the music back. I'm on Windows 11, so I'm guessing something changed. Does anyone have an updated fix for this? If not I may just reinstall from disc, which kind of defeats the purpose of the GOG version.

Its not a GOG version issue, Steam has it as well it seems, believe its more a "digital edition" v "physical edition" issue.

Anyone, feel free to correct/complement to the following: to my understanding this happens because the audio tracks were converted to audio files and the .dll that makes the "connection" is winmm.dll. Using WINE did the trick on my case via: WINEDLLOVERRIDES="winmm.dll=n,b" %command%.

Since I am using SteamOS, the above may now work you, however, am aware a potential solution that may help you:
(but note that I have not tested/tried it.... but think it may point you in the right direction)

[url=https://www.pcgamingwiki.com/wiki/Star_Wars:_Jedi_Knight_-_Dark_Forces_II#Music_issues]https://www.pcgamingwiki.com/wiki/Star_Wars:_Jedi_Knight_-_Dark_Forces_II#Music_issues[/url]

Yeah I think it played the audio tracks from the CD. I tried several wrappers and nothing worked. I think I will try them on my older PC with Windows 10. I've also had flickering texture issues which I never had with my 16 year old PC. If I had any foresight I would have kept my old Windows 98 PC from that period to run these correctly! Thanks for the info though!

Know the feeling, started dropping Windows last year as it became a pain to play older games.

One thing I can try, is to check if I can find the winmm.dll from the Deck and compare with the .dll from the link had shared with you (which i assumed you had tried already with no success)

I think the fix I tried had several versions of that file and neither worked.

I thought about maybe putting another hard drive in my old PC with Windows 98 on it to run old games, but I'm not sure if I could even find drivers for that old card (GTX 285 OC). So no idea if or how that would work.

Winmn.dll from GOG is 64kb v the Wine version which is around 821kb, i.e. substantially different, however, funny thing:

On my 5th gen intel wo dedicated GPU win10, the game now crashes when 3D acceleration is off, but with it on the screen goes black except the hud/crosshair (but you can play the game...blindfold mode difficulty)

On the daily driver an 8th gen intel w a dedicated GPU, game runs only wo 3D acceleration only at 320x240 with music using the GOG wrapper! But does not run at all with 3D acceleration on...

Seems the hw combo and Win do cause issues with older games (now i remember exactly why I gave up on Win for retro gaming). Music working but not being able to play with higher res was not the outcome I was expecting...

Can you get a hold of the winmn.dll and give a shot? - reckon you can install Wine and get the .dll = download from the secure/safe source