Backupper - Error code 21 - Not enough memory

I am trying do a Increment Backup, but it failed. Occurs the error:

"Error code 21. Not enough memory, please close and re-run the program and try again, or you could reboot computer and release more memory to retry." 

Is not enough 32GB RAM? Or is it a disk full exception? I have 460GB free on disk. 

My setup: i7 4790 @ 3.6GHz, 32GB DDR3 @ 1600 MHz, ASUS B85M-E

Storage unit: NAS D-Link DNS-320L, 3x Hitachi 2TB Sata3 7200rpm HUA722020ala331

There a option for Backupper 64bits?

Can someone help me? Thanks