Another scenery in conflict.
Especially the objects in the air, are the result of another scenery for the same area, that incorrrectly set the altitude to 0, while Cloud9 EHAM has it below 0, where it should be.
I'm sorry not be able to be more precise but, it's 100% another scenery for the area. It might be difficult to find, because there are some freeware sceneries for the same area, that put .BGL even in the default scenery folder, and some even modify the default scenery so, you really need to remember which scenery you installed, and revert to their own readme, hoping they explain which files they added and where.
A note: if use the current FSDT EHAM installer that is found on this site, there's no need to install the CD anymore. You can even throw away the CD: the only thing that is valuable there, it's your Serial Number.
The current version of the Addon Manager that comes with EHAM, will let you to insert the Serial Number directly and, since the 1.04 Trial can be unlocked into Full version with the Serial Number (it's not an "update", it's a full version ), you can simply install JUST the 1.04, and it will accept your CD Serial without any problems.