And then, everything went haywire...

I like to think of myself as a subject matter expert when it comes to GTA modding, but my latest problem has put that discussion to bed, as I am completely clueless as to what to do to solve this. 

My game is heavily modified with included lots of cars, scripts, peds, sounds, etc. It was working flawlessly on the latest version with gunrunning and eveything. However, I booted it up today and everything was (excuse my French) fucked. I couldn't spawn any addon vehicles, as I would get an "Invalid Model" error in simple native trainer/trainverv and this message was also displayed when trying to spawn mp vehicles (benny's, etc.). EUP Menu said EUP l&o wasn't installed. Most confusing of all, though, is that police2,3,4,fbi,fbi2, etc etc all reverted back to vanilla models. Only Police remained, the lone non-els CVPI. (Also my Landcruiser replacing Calalcade still worked.) 

What the hell??

I added new gameconfigs, reinstalled prerequisites, reinstalled scripthookv(dotnet), reinstalled  EUP, fiddled with dlclist adn extratitleupdate and the whole shebang, but to no avail. There hasn't been some secret game breaking update has there? 

Note: sound mods and smy_swat01 still work as well as LSPDFR.

Any help is MUCH appreciated.