Doubt it's going to work on Windows 8, there is a problem with IE9,10, and 11 with the updater.
Do you have the Eleven Rack drivers installed?
Do you have access to a Windows 7 or Windows XP PC? It's pretty embarrassing that they haven't fixed this in over 3 years since I first brought it to their attention before the ERXP was even released.
More than likely you will need to get to a compatible PC and have them reset the Serial.
Question....
Did you buy the 11R and ERXP from the same person? Is this a business or individual?