Back in the old days, you could run VCV with no audio device. I realize that now, “for reasons”, you always need to have an audio device active. But it there something more you need to do? Can’t seem to get anything to run no matter what!
ok, after an hour, it turned out it was some whack plugin that was in my autosave, somewhere off the screen. Still, shouldn’t happen with plugins from the library, but whatever. Deleted the auto save and it works again.
Whoops, never mind, missed the post above… 
Yes. As far as I recall Andrew telling it in an old development posting, Rack was re-architected for v2 in such a way, that the (chosen-as-master) audio module now basically drives the “engine” of Rack, whereas before the engine was “driving itself”. So in v2 if you have no audio module you have no engine-driver and nothing happens.
Nope
I’m gonna ask a silly, embarrasing question: Are you 100% sure, that with that exact driver chosen, and that exact interface chosen, and that exact samplerate chosen, any other software in your system can make a sound through it?
Haha, yeah, a mystery. I did check all the sr stuff, and it did seem slightly wonky. I still think it was something in that patch, but who knows? I definitely could hav had bad setttings, although I did mess around with that quite a bit. Befor I finally deleted the auto save.