It is first important to inspect your connection from the host computer to the ActiveRAID, and make sure you are trying to communicate to the right controller with the associated IP address of your subnet. Bonjour is a strong tool that often discovers the ActiveRAID even though the subnets differ. However, when you attempt to access the system you will need to be within that same subnet.
If all of the above is correct you may want to restart the Active Viewer and select your ActiveRAID again, or restart the entire ActiveRAID. If you choose to restart the ActiveRAID make sure any fibre channel hosts are shutdown. You can use the Active Admin to shut it down or hold the power button down for 5 seconds.