Yes i do have release audio driver ticked. Im still on sierra on a 2013 mac pro, cubase 8.5, i have 9 and 10 bought and installed but keen to finish projects on 8.5 before moving on.
My audio interface is a motu 828x thunderbolt.
As for the relevance of an audio track. When trying to find a way round this problem, ie get the vsti playing back again, i discovered if i reset the audio engine (flick from core audio back to motu) the vsti would play again. I then discoveres that if if i just inserted or deleted any audio track, the vsti would start playing again. So thats what i have to do, which you can imagine is a massive pain in the ass. I open piano roll, move a few notes, then press play and it that vsti doesnt play, so i insert an empty audio track. And then it plays. Massively cumbersome…
Its difficult to track it down to a plug in or certain vsti instance as well, as projects often exceed over 100 tracks and 64 vstis etc an assortment of plug ins(all legit) and some master buss processing.
Thank you guys for the responses btw.