I encountered this error today, where I was prohibited to delete a network object. The “where used” referred to the firewall object and the following context string: “interfaces->{F618DF02-1BE7-4A2E-AC7E-B22C44F1ED22}->security->netaccess->allowed”

The solution, althrough a bit tricky to find, was very simple. The firewall’s anti-spoofing on the external interface was configured to not check packets with IP-addresses originating from this specified network object.

Removing this “do not check”-configuration sorted the issue and allowed me to delete the network object.

Gos