please make sure that the file "TNP_ALT.bgl" is inside your
"FSX/Scenery/World/scenery" folder. This folder should also be registered
in your scenery library at the very bottom.
Also ORBX states in this thread to de-activate files:
In order to achieve compatibility with SCA, some SCA files need to be deactivated:
DEACTIVATE: (by renaming from .bgl to .bgl.off)
>>> in \ORBX\FTX_NA\FTX_NA_SCA05_SCENERY\scenery
>>> in \Scenery\World\Scenery