Insufficient Privileges to perform this operation. Contact your Administrator.

Insufficient Privileges to perform this operation. Contact your Administrator.

When I entered a note for a contact then hit save, I received the error message above.  When I did so on another contact, it seemed to work.  When I went back to the original contact, it saved OK, but a thin vertical red line appeared on the left side of the note, then faded away.  Why is that, please?  Thank you.