I have read here in the forum that I only fill in the serial of ORD in the field for the ZRH serial and so ZRH will work.
You read it wrong. Who wrote that ?
I did it 
and it works.
No, it doesn't.
A little bit strange , but what can I do to get the scenery after regisering
Of course, putting the JFK serial for JFK, the KORD serial for KORD and only then you can buu Zurich for free with the free coupon, that will get you a 3rd serial tor Zurich.
Please, contact us via email, so we can instruct you how to reset everything and putting each serial to the correct place.
