You say the live update pops out on FSX.....well I just installed this for the first time and just started working with it and as I said never noticed any pop up updates...
If you installed it for the first time, you are updated, so you shouldn't see any further Live Update messages. I've based my reply on your report, with BOTH Addon Manager and Couatl menus being visible, and the Couatl menu disappearing ONLY at KJFK and KLAX.
This seems to indicate that you don't have the latest Addon Manager files, which is odd, since every FSDT installer (scenery, GSX, etc ) always downloads the very latest version of everything.
Since you responded that this past "major update" deals with the problems I am having installing JFK and LAX can you l
just send me the update or whatever needed files I need to correct the couatl problem?
As I've said:
You can download the Stand-Alone Addon Manager installer from any "Info" page of every product, on the left column of the web page.
That's the only thing you need to do to be sure everything is updated. Just do it after the sceneries, because that installer only updates sceneries that are found when the installer runs.