Hello darkness, my old friend…
This issue has persisted from 8.5 through to 9.0.1. I realize there is a video engine rehaul in the works (Steinberg staff have said it is tentatively due spring 2017). But I feel I need to reiterate this issue here now with version 9.
Same elusive causes - it’s almost impossible to nail down a way to reproduce the bug but it definitely happens a lot - daily, even.
Most notably, this hang happens after I’ve had a very large project open, or if I’ve left Cubase open for a long time (many hours or overnight).