Network interface of a server has 2 or more configured IP addresses and the DHCP server itself is configured to serve subnets to whose the second (or any next, not just the first) IP address belongs.
DHCP server is able to discover only the first IP address of network interface and therefore is able to serve only subnets to which only the first address belongs. If the server is configured to serve only subnet to which the second or any next IP address of the network interface belong, it refuses to start with 'No subnet declaration for ...' message.
Network interface addresses discovery code was completely changed.
DHCP server is now able to find all addresses of a network interface and therefore is able to serve subnets to which these adressess belong.