Error Code 0x80070013 Windows 10??

I have a question about this error code -- 0x80070013 that I received this every week after the backup completed. I am not using Windows 10 backup and used another program with NTI Backup Now EZ 4 that come with the external hard drive that I have is Toshiba Canvio 2 TB. I setup the backup every Sunday while I am at church. My question is why is that message popped up every Sunday after I clicked " Backup did not complete " Well I did check to see my back up with the date on external hard drive and the job was done with no problem. Should I ignore this or need to be fixed.

Let me know about this and what should I do to correct the problem.

Thank you,

John