Scrivener is crashing everytime I close a window

Hello…

Scrivener is crashing and I get crash reports sometimes when I close a window by pressing the red X button.
This is new… I still can see the save- bar for a second that tells me that the state is saved, but then it crashes instead of returning to the start screen.

Is this a known problem?

What does the crash report say, please?

Also, does it matter which window you close? That is, do all projects behave the same?

And finally, what if you use the File -> Close Window command instead?

Katherine