I have installed an RRD-6NA dimmer in a 4 year old system running 6.3. It will not activate, nor will it return to factory settings (I have tried to press 3 times and hold, 4 times and hold, etc and the LED's will not scroll). I tried updating from 6.3 to 11.6 to see if that would help. 6.3 finds my repeater but 11.6 won't, even though the serial number and ip address in 11.6 are correct. I have rebooted the repeater and removed and restored power to the 6NA - no change. I still have the 6.3 version software and file. Thoughts, please.