Edit: Indeed. A clean install fixed the issue. No idea what the issue was, since it was already a pretty new install.
Thanks for the reply. I'll do a clean install of the game and report back then. The new system is super annoying. I wish they would add a option to use the old "random" music system, which just plays all tracks in the environment folder, since i prefer diversity over speciality. The mood system is a nice addition but in the end it just limits the music pool in a game, where the music can become quickly repetitive.