Aoe DE doesn't save anything after closing the game

All the options (sound, language, etc) are getting resetted to default when quitting the game. Also, all saved games and campaign progress disappear as well. Especially not saving the campaign progress (the already finished missions) is pretty bad. I would appreciate if this could get fixed by the devs or if anyone has some ideas how I could solve this myself. As I don't really see other people complaining about it, this might be a rare bug...