Hi all:I have made a scenery for a small aerodrome near my city, LEMR (Oviedo, Spain). I must add some terrain for a taxiway and an apron that doesn't fit in the default trip. I have made the AFD with AFX, and I have used SBuilderX to make the exclude (airport boundaries, autogen and flatten, three polygons in one final BGL file).My problem occurs ONLY the first time I start FSX after initialition of my computer. Then, I can't see the new apron and taxiway when I am over the ground or near the ground. But they are there, in same way, because if a go to aerial vue, after elevating several times the AFD elements appear.If I close FSX and I start again, I can see perfectly my airport from the ground, and all works perfectly in this session and all the next ones. The problem occurs again when I close my computer and I turn on it again.I have read the tutorials of Luis Feliz Tirado and Scott Smarts, and I have explored several forums, but I haven't found a reference to this strange behaviour.Anybody could help me? Thanks a lot in advance.F

I hope the problem is solved. I have reduced the height of the flatten polygon from 165 m.(airport reference height in FSX) to 164 m., and now it works well since the firs time I start FSX.I still don't know why this happens, but after reinitiating many times the PC and the sim, in several conditions, I think all is fine.Thanks for the attention, however. I hope this short drama could serve to somebody that find the same problem in the future.Regards,felixfer