Hi,
my first test backup just finished with errors and warnings. I've noticed that because I was at the PC at the time. I also noticed that there is a countdown on the notification. I don't understand this. How can there be any expiration on a notification of this importance by default? This is something that may be useful later after some experience with one's backups and the app, but by default? It makes no sense.
Please send us the last backup log for that job, to see what was the error/warning about. It is important as there are different error/warning types.
In Backup4all, you can set which notification messages will expire or not in File->Options->Notifications.