I am not as familiar with Fusion as many here are (perhaps a moderator can move this thread?) but in the VM settings you can specify whether the VM connects directly to the network with it's own ip address (bridged) or has a "virtual" ip address and lets all communication pass through the program/host machine (NAT).
If you can surf, etc from the VM then networking does not seem to be your problem. The next steps probably involve troubleshooting the app itself, which this forum will not likely be able to do. Could be a license issue or some security protection of the app itself. Do you have support for this app?
