Hey Matt,
Adam directed you down the right path. If you haven't already, you can download the most up-to-date firmware here: https://www.neptunesystems.com/support/sw-updates/">https://www.neptunesystems.com/support/sw-updates/</a>
It has the Apex software in a package that will allow you to find the controller on your network and update the firmware. Be sure not to update over wireless. You need to have the controller and your computer connect hard lined through ethernet. If you are still having problems, other areas to look at would be the IP and Gateway for the controller, as well as ensuring that you have DHCP enabled through the display. If all else fails, I highly suggest factory resetting the controller using the display (if you have one). If you don't LMK, I can let you borrow mine. Either way, you will have to download the software above.
I had the same problem today, but I couldn't even access it through fusion. I forgot that I had set a specific IP and GW address that our IT folks had given me for running on our company network. Once I reconfigured the IP and Gateway, updated the firmware, as well as enabled DHCP, I was able to resolve the issue.