Hi there and thank you for your reply... yes of course it is holiday-season. I am sorry, I honestly did not think about that...
As for your solution: I did that. No error Message, just confirmation, that the product has been activated. However, there's no File in the Module folder and also no entry in the P3D menu in the Sim (where it used to be). There's no antivirus thwarting my efforts - I made sure of that. There's also no entry in the ADD-ONS Manager. I started the sim afterwards and it didn't ask me if I'd like to allow the respective dll to be activated AND I loaded LHBP, which was there but without the buildings and such (looks kind of funny how all the AI would lineup neatly before these gaping holes in the ground) - speaking of which: could there be an issue with AI traffic maybe using a .bgl that's hindering you scenery to function properly?
Is there anything else I could try? Also I am trying to understand what causes this glitch. The scenery used to work well beforehand. The lack of an error message seems to indicate, that maybe there's an activation limit reached. I can - of course - provide a proof of purchase should you so require.
Regards,
Peter