Norton online back up error message code A2222

I hope someone can help on this.  I have been backing up for about 3 or 4 days and got to 37 per cent transferred.  Then all of a sudden I get the notification that the back up has failed with the error message code A2222.  Can I start again from where it left off or do I have to go back to the beginning?  If it is the latter then I think I really want to cancel my online back up subscription - or at least the additional space I purchased which is turning out to be an expensive white elephant.  I am very depressed!!  Can someone help?  Thanks