Just spent the last hour troubleshooting a Boson NetSim Lab that wasn't working. Ended up being the simulator was designed to handle the commands in a certain way otherwise it would break the configuration.
Changing EIGRP network statements form
network 192.168.1.0
network 192.168.100.0
to
network 192.168.0.0 0.0.255.255
If you did
no network 192.168.1.0
no network 192.168.100.0
network 192.168.0.0 0.0.255.255
everything would break, the only way to get it working was to follow their script and do a
no router eigrp 100
router eigrp 100
network 192.168.0.0 0.0.255.255
If anyone is curious it's the Lab: "EIGRP and Wildcard Masks"