I just encountered this problem recently.
I added a new instrument to my project (which I have a TON of VST instruments —
(i.e. 17 VST instruments with about 8 (omnisphere) to 16 channels (spitfire audio and VSL) of instruments (about 62 gigs of sample data)).
I noticed that sometimes, after a while of playing just fine, it stops playing KeyScape and/or Omnisphere?
The strangest thing is, that if I quit the project (no small task considering how big the project is adn how much memory needs to be freed) and re-open it, everything plays fine for a while, then it seemingly randomly quits a particular VST instrument.
I searched around on the forum and many suggested increasing the buffer size. I did this but to no avail.
Thank you for ANY help you can give me,