You are probably running the sim in "Compatibility" mode, which causes the video drivers to misbehave and cause that problem. Be sure that NO checkmark is enabled in the Compatibility page for the FSX.EXE file.
Also, I see some black textures in the objects, which seems to indicate you must have moved manually some scenery files, which you cannot do: the scenery must reside in the fsdreamteam folder under the main FSX folder, which is where the installer installs into. If you move files around, it won't work anymore.