I'm trying to auto-discover a network 192.168.12.192/27 so I enter "192.168.12.192" in the "Network IP" field, and select "255.255.255.224" as the subnet mask. When I hit "Add Network" it says "Please enter a valid Network Address". 192.168.12.192 bitwise ANDed with 255.255.255.224 equals 192.168.12.192, so it is a valid network address.
Why can't I enter it? It seems a zero is required in the last octet for it to be accepted.