https://bugs.winehq.org/show_bug.cgi?id=51063
--- Comment #8 from Sveinar Søpler cybermax@dexter.no --- I did not have any issues running DCS_updater.exe with wine-staging-6.8.
I did not download the whole 47GB game, but running DCS_updater.exe stopping it and re-run it seemed to work without any complaints about os. Is it something that happens only once the full game is installed?
Could you test with wine-staging-6.8 and if it still fails, maybe just recreate your prefix with wine-staging-6.8 and just copy the Program Files/Eagle Dynamics folder over to the new prefix and run the DCS_updater.exe then? Cannot guarantee how it works, but hopefully it would be "smart" enough to do a repair or something without the need to download the full game again?