Hello, if i am not wrong, the copy / paste option is included with this mod.
I will makes it short.
I try to make an airport with the DLC, therefor i created a runway, and because i wanted to copy past it elswhere, i did just that. However, the runway isnt a prop like the other, it's not a road. And it didnt copy correctly. The problem is that i pasted it because i was thinking that it was simply a visual bug. However it is not just a visual glitch.

What eneded up happening ist hat a part of the runway sunk to the bottom of the map, far below the eyes can see (usualy). The newly created object can't be deleted, creating a small rectagular hole in the middle of the airport area.