UnknownUnknown
Unknown(an hour with Proton)The problem is "bad serial number given in Setup" - there is nowhere to input the serial. I found the answer here: https://github.com/ValveSoftware/Proton/issues/767. I followed the comments to convert key to hex (just use the terminal) and updated system.reg (add commas after each pair of characters of your hexed key). After that, game runs flawlessly as far as I can tell.
Unknown(an hour with Proton)UnknownGame runs to splashscreen for about a second then displays message: "Bad serial number given in Setup". There is no way to input serial number. Apparently fix exist: https://forums.bohemia.net/forums/topic/130923-bad-serial-number-given-in-setup-error-tried-everything/ but I don't know how to run regedit in Proton. I tried by winerticks, but regedit window is empty. It's a shame really, because I managed to run Arma II OA sucesfully.
Unknown
