Scrivener keeps shutting down and not saving recent changes

I think this might be the 5th time that the following message appears as I’m working –– ‘There was a problem saving the project __.docx. Not all recent edits could be saved. The project will now close.’ –– and I don’t have an option but to press ‘OK’. My window then closes, and if I try to open any project again it takes about 10 seconds before it shuts down again. The worst thing is that it might stay like this for days, so that I don’t know when it’s safe to work with Scrivener again (I end up avoiding it for months).
I did notice that this normally happens when I have a file open for many hours, or if I have more than one open at the same time. I can work with no problems for a while and suddenly it happens. But this should not be a problem as my work requires long hours…
Oh yeah… and when it shuts down, the day’s work is normally lost.
I wonder if it has to do with storage space on my Mac?

Update: after a while, if I try to open Scrivener it won’t even let me –– the message ‘The application “Scrivener” can’t be opened. -34’ appears.

Scrivener doesn’t save .docx documents, so you must be doing something special to get this.

On top of that, a Scrivener project (projectname.scriv) is not a file, it’s really a folder looking but like a file in Finder. Each Binder document in your project is a file saved in a subfolder of the .scriv project folder. And the files are of type .rtf, not .docx

So what are you trying to do when you get the “problem” dialogue window?

Have you restarted your Mac?

Error 34 is a system fault. You should look into having your Mac diagnosed and potentially repaired (at the least run Disk First Aid). It is not a specific error, it simply means that when the system tried to write a file, it didn’t happen.