A best practice is to make sure the db is backed up every day.
However, ACT, pay attention here ...
It is not uncommon that, during the process of the day, a document or two had been left open during the day. When the scheduled backup starts it fails b/c the user did not close the document(s).
Can the development team give consideration to modifying the backup process with a notice to the user that because a document was left open, no attachments were backed up.
There could be a number of reasons why a document was open; however, the backup should be completed without attachments. The reason it should be skipped is because the db doesn't know if the document is in the process of being changed or just open for reading.
The necessity of the core db being backed up is critical.
And if you are not backing up every day, please adopt this best practice to schedule an automatic daily backup.