Often crashing when I try to look at top level of project

I have a large book project. When I try to look at the project as a whole, Scrivener crashes.
I just tried to see how large is it, and noticed that the word count for the whole project is wildly off, showing the project as a whole as much smaller than a single section - perhaps this is related?

I’m quite concerned, as the book is going to get larger. There is very little media, pictures, etc. but many subdocuments.

This is on Windows 10, a desktop with plenty of memory and disk space.
This has been happening for several weeks. I just installed and the problem is still there.

Screenshot 2018-10-07 10.35.30.png