This happens to me every time now. I’ve trashed prefs, re-installed, updated drivers etc.
In my large orchestral templates using PLAY and VI, every time I try to close Cubase it hangs and shows up in activity monitor as “(Not Responding)”. It seems to me that PLAY is the culprit here and Cubase hangs as it tried to unload all the PLAY instances from memory, but I can’t find a workaround. VE Pro 6 closes no problem as do Kontakt instruments. I’m on a Mac Pro 12 core running latest version of El Capitan.