Only free to play content works ("Failed to get authorization data. Error code is: 500")
- Download Proton 6.20-GE-1 (yes, it has to be this version AFAIK)
- Go to ~/.local/share/Steam and create a folder named
compatibilitytools.d
- Extract the downloaded archive in the folder you just created
- (Re)Launch Steam
- Right click on DCS > Properties... > COMPATIBILITY
- Make sure "Force the use of a specific Steam Play compatibility tool" is checked