"Cubase 9 has Stopped working" - happens on Save

I keep getting a “Cubase 9 has Stopped working” message and Cubase crashes - happens on Save - ot every time but every few saves.

Any ideas how to troubleshoot this and rescue my project?

Every few times on all projects or just specific ones? Are here specific plugins involved? Have you tried with a clean template and saving this repeatedly?

Seems to happen on one particular project - relatively large one, over 40 000 KB. I don’t think there are any unusual plug ins on this project and its been working ok over a number of weeks.