I'm currently having difficulty getting my RNS-E to read the nav DVD.
I've replaced the laser in the RNS-E and it plays music CD's ok. So pretty sure I've installed it correctly.
I've even tried burning some replacement disks but still having no joy.
As I don't know if its the laser or disc's that's a problem.. I'd be interested to know if there is anyone near me that also has an RNS-E which I can try my discs in? and maybe try your disc in my RNS-E.
Then I can work out what part is faulty and replace it!
Happy to donate a 2013 disc to anyone that can help.. as long as you have an official 2013 disc of course (no dodgy business here!)