re: Mathematica 13.0 (home edition) running on macOS Monterey Version 12.5

Issue

I worked on an existing notebook yesterday morning and saved the notebook at 11:05 AM without incident.

After further work, some 20 minutes later, I attempted to save the notebook again and the following popped up:

Between saving the document at 11:05 AM and attempting to save it again, I made no changes to permissions of directories or anything else.

I only edited some simple code (which worked and continues to work).

Of note:

I have no problems saving other kinds of files. I could (at the time) save the notebook to a different directory (file folder).

Today:

This issue has now spread to other directories and other notebooks.

I do not have this issue when saving other types of files; it seems, at least for now, a Mathematica issue.

Thoughts appreciated.