Why won’t Battle of Stalingrad load through Steam?

[Blesk]

I bought the game 3 days ago, downloaded and saw it’s not working. I did an hour long search, tried a lot of things and evantually, linked my Steam account and official site account. When I run the game manually from the file it will load, I sign and see everything. But I can’t play any career/mission etc because it thinks I don’t have it purchased while I already purchased it on Steam which is linked? Can anyone help please? (No reinstall, it takes me 3 days to download it again, please, anything else)

[LukeFF]

You have to launch through Steam to see all of your content, if that's where you originally bought the game.