Same for me. Reloading scenery broke the airports infos, no more country and city info. As well as research of those.
When typing a country in research window, eg France, I get only 3 airports…
I tried reinstalling LNM fresh, but it seems the info just doesn’t get caught from the game scenery files (or they have been removed?).
I know LNM keeps some files backups, but I’m not sure if it does for the scenery, and which it would be in this attached
list :