First off, I have a solution to my problem: start my neighbourhood again, and then everything works. But, I have no idea why this happened so I'm wondering if anyone can shed any light
I made a new neighbourhood very recently, in fact so recently and with so few sims/lots that I hadn't even made a backup (fail, I know). Today I quit my game to install some mini beach lots (which I had been looking for forever because I am dumb and can't use searches properly). I went back in and got a "Lol you uninstalled FT, retard" message. I've had this kinda thing before: either changing the registry to actually point to the right place instead of the new location of "IGOISJOGIJEO ERJALLOLOLOLOL" or simply installing the EP over the top again fixes it. Not this time! And it wouldn't even install properly because it couldn't "update" :S
I tried removing the lots I'd installed, being as that was what had actually changed, still "where's FT lol". Took out all the lots, not just those: same. Took out my whole Documents\The Sims 2 folder - it semi-broke when regenerating neighbourhoods (maybe I went a bit overboard with the empty templates!) but ~*magically*~ FT was there again. I narrowed it down to my neighbourhood folder - with an empty one, I still have FT. But how did this happen? How can the presence of a neighbourhood that worked literally 2 minutes ago make the game think a whole EP is missing? :/
(Also - I don't need to get another securom-free .exe for FT, as I'm running from a later EP, right? Just checking...)
EDIT: Well, I'm glad this was moved here because it's STILL BROKEN ARARAAARARR ;_; It lied to me