Hi everyone, On the forum there have been a couple of people who tried creating an iso backup and it only showed a 0 byte file. I have confirmed with my vm testbed. The same thing works fine for CU169. After looking through code I have found that Core Update 169  and 170 file name order is different. The arch is placed in a different location https://downloads.ipfire.org/releases/ipfire-2.x/2.27-core169/ipfire-2.27.x86_64-full-core169.iso https://downloads.ipfire.org/releases/ipfire-2.x/2.27-core170/ipfire-2.27-core170-x86_64.iso This means that backup.pl is not able to find the Core Update 170 iso from the downloads site. Regards, Adolf.