The Eleven Rack updater is the
ERXP. It's a paid firmware upgrade that gives you several more amps and effects above what was included with the initial release of the Eleven Rack.
From your post however, it sounds like you probably already have the ERXP installed since Avid has been including the upgraded firmware for several years now with new Eleven Rack units.
You can tell if you have the ERXP by checking if you have all the amps listed on the
Eleven Rack page
OR (and this is the better way to check)
Check the firmware version of your Eleven Rack. If it says 2.0.x, then you have the latest firmware and you DO NOT need to update the Eleven Rack.
VIDEO:
How to check the Eleven Rack Firmware
https://www.youtube.com/watch?v=sFclFceQDg0