Accessing EERO Router via PC Web Browser?

I've seen many articles that state you can connect to the EERO router in your home through a web browser. I've done this for decades with previous routers. My network was set up with the router being 192.168.4.1. When I enter that address in the Firefox Browser I get a message that says this client isn't allowed access. I can't figure out how to allow that. Right now I have to control the network via my iPhone app. I'd rather use my PC - Windows 7. Matt See attachment picture for error message.