Nuendo 11 crashing - editing clip fades/crossfades stopping/starting playing - NO Log?

I am using Nuendo 11 for a small post production project and am having crash issues - almost 1 every 1.5hrs now.

I am editing cross fades, and clip lengths - press play, press stop, adjust, press play, press stop…

What happens just before the crash is Nuendo slows down for half a second to a second resumes, then crashes in a heap. I’ve been trying to find log files for this crash - but I don’t think it even writes a log file - the application shuts down like it never existed in the first place.

Has anyone else been experiencing this and knows what may be causing it?

All plugins are legal:
Waves L2, WLM, S1, C4 mono, Q4
Izotope Ozone 9
J37 Stereo
SPL Deverb (not actively on a track with signal) - earlier in the time line.

windows or mac ?

if windows, what is in the windows (application) event log ?