please download and install the lastest Stand-Alone addon manager"
need less to say I have done this and re downloaded your airports i have and still the message repeats.
The message said to download the lastest Stand-Alone addon manager, there wasn't any need to download all the sceneries.
It's very likely the problem it's caused by your browser that played a trick on you, and has cached the Addon Manager installer so, you are still getting the previous version which was released with KLAX 1.0
bglmanx.dll version is 2.8.0.8
That doesn't count, the .dll can't be outdated, because every installed (even the old ones) get it online automatically, and they are not tricked by the browser cache so, it's not possible to get an outdated .dll by mistake.
However, in this case you need the whole Stand-Alone Addon Manager INSTALLER to be 2.8.0.8 so, be sure you have that one (you probably haven't, otherwise you wouldn't see that message), and not the previous version.
Clearing the browser cache before downloading should fix the issue.