It seems you have part of a default building, which indicates another scenery in conflict.
Whenever you suspect there might be something "default" or not right with a scenery, the cause is almost always a duplicate AFCAD from another product, even not a scenery. The worse offenders are AFCADs coming with AI Traffic Package like Traffic 360, My Traffic, Traffic X, etc.
You can use the free "FSX Airport Scanner" utility to search for file duplicates at any airport.
