The reason for receiving this message is most likely because the location where you are trying to save is not available. This could be when you are trying to save to:
and external drive (or USB) and the connection to the drive was lost
to a network drive and your IT team has locked the file for some reason.
Solution
You should be able to click on the "Save as" option and you can save to your local hard drive.
AuditSoft does make periodic backups of your audit file. You can read more here: