I got this very recently (Base version, GOG ID 1242541569, version 1.5.1.712), so I don't know it it worked before and until when, but on my W7 it won't even start. The store page lists W7 SP1 as requirement, only the "Spacers Choice" says W10 is required. Has there been an update that changed the requirements for the base version also?

I'm currently in the middle of the third verify / repair. I'd try to d/l the entire installer but it's 55GB and probably in vain if the repair can't fix it. Plus if it wants to unpack to C: I don't even have enough space there, thus I'm stuck with installing through Galaxy ATM.