So, I've been playing the game for an entire week no without any crashes or problems but now, for some reason, whenever I try to start the game up it instantly turns to "Witcher 3 has stopped working".

The retarded part about this whole affair is that the game has been working fine just a few hours ago, I went out for a bit, got back home and now it won't even start anymore.
Tried a completely fresh reinstall of both GOG Galaxy and the game without any results, nor does installing the game without GOG Galaxy work.

Did anyone else experience this kind of seemingly sorcery already and, more importantly, how did you fix it?