My first actual crash! 
I had this year’s NaNo open, with a few files in Research and some index cards, but no text in that one.
I also had a project with a 50k-ish word manuscript, broken into 25 files, nothing else in the project, since it’s an older work. I had the Draft selected, and then the fullscreen editor. I was scrolling down, and – boom. “Scrivener.exe has stopped working”
In an attempt to recreate the problem, I opened only the bigger project, and went into fullscreen, and was able to scroll to my heart’s content. I then opened the smaller project, went back to the big one, scrolled… boom.
To see if it really was just that combination, I tried going fullscreen on the smaller project (which is a lot of white space, lol), that works fine. I also tried going fullscreen on just a file (not the whole Draft) on the larger project, and that works fine, too.
Obviously, a workaround exists. 
Don’t go into fullscreen on Draft of a large project if you have more than one project open.