This error is indicating that one of the networks configurations is incorrect. Usually the error will include more details like the example below:
[5]:[2011/12/08] 10.21.10.100:cpu0: (3313) UserInputError:BadNetwork thrown by Network::Network: Mismatching address/netmask supplied with network: 192.168.0.60/24. Host part of address must be 0.
Using this example, the error is telling us that a network configuration of 192.168.0.60 with a /24 subnet is incorrect since you are stating that the network portion is 192.168.0 and for that the HOST portion MUST be 0. Assuming we still want to use the /24, the address needs to change to 192.168.0.0/24.