Hello Umberto,
tks for the link.
I found the error in my prepar3d.cfg, which was that under [Scenery] section I had a double entry,
so twice the entry SCENERY_DRAW_DISTANCE
One
"SCENERY_DRAW_DISTANCE=53333.335938"
resp the other one was
"SCENERY_DRAW_DISTANCE=32000.000000".
I put away with one of them, restarted the FSDT update and things went through fine, and SSAA optimized ground textures installed.
So my fault here, the problem sits in front of the computer.....