So I guess anyone who purchased the R18 version on this website in the past is screwed? Well that sucks. Guess I'm out of luck here and stuck with the old R18 build.
EDIT: Never mind. There is an actual ingame "update game" option in the R18 build that fixes that problem. I'm just blind and stupid XD
I'm extremely lucky I still had the game installed. If you don't have a back-up or installed version of the game, yeah, you might actually be in a bit of a pickle.