Do you get a page not found error or do you get the welcome to rio karma screen and get an error when launching RMML.

You can pick any number you want for the ip address as long as it isn't the same one you used in the pc. You also have to make the pc ip address in the same range and use the same subnet mask for the karma and the pc. Like use 192.168.1.10 for the pc and 192.168.1.11 for the karma and use 255.255.255.000 for the subnet for both.

You can also try just downloading the .jar file from http://www.inzyme.com/rio/index.html and just run it without the webbrowser.