Your port settings are likely an issue or you have another network-related issue. The printer should have an IP address. If you have it set to auto, you might consider setting it to a static rather than relying on the Brother software to auto sense the printer. Even if you do not do this, you should be able to ping its current address which should be available from the printer's console. If you cannot do this you will need to look into your network/firewall connectivity issue. If you can do this then you know the problem computer can communicate over the network to it. Try creating a new network port carrying the current IP address (why I recommend a static so it does not change) and running through the wizard to manually create a new printer instance using the second method.
If the address is 192.168.1.50.