Hi there!
I am facing an annoying issue with all the fsdt airports I have(lszh,lsgg,kord,kjfk,kfll,klax,kdfw, klas). Actually it appeared for the first time when all buildings disappeared(which is an acknowledged issue). As a result of this I decided to uninstall the secenries altogether(I answered yes to both question concering the coualt engine and the addon manager) with my antivirus switched off. Afterwards I rebooted my computer, then I excluded coualt.exe and bglmanx.dll from my antivirus scan and then I reinstalled all the aiports. Eventually it seemed that this process solved the issue, but actually it didn't.
Indeed all aiports displayed as they should have in the game twice but the third time all buildings and runway textures disappeared again.
I guess it's worth mentioning I've repeated the whole process something like 3 times without solving my problem.
Hopefully you could bring some lights so as to get these airports to work again.
Thanks in advance