I've looked and it seems some people have the same problem, but since I've not seen a detailed topic I've decide to create a new one.
I know about this:
http://www.creationkit.com/World_Spaces
http://www.creationkit.com/Landscape
And for example this tutorial: http://www.youtube.com/watch?v=W0XYJm1nWec
I've tried with parent worldspace and without, I've tried with the land at 0 and other heights, same for water. Grass always shows in the CK but it doesn't appear in game, here's the last trial (images):
http://www.mediafire.com/convkey/8c00/x36bx5xz56gcaa05g.jpg
In the CK:
http://www.mediafire.com/convkey/476c/a5d488hy1t6jr385g.jpg
Ingame:
http://www.mediafire.com/convkey/f029/jnz2f649c1dq5wc5g.jpg
As you can see the texture appears but no 3D models for grass.
Video of the problem (only 2 minutes): http://www.youtube.com/watch?v=wv0qNf_pl9s&feature=youtu.be
Help?
Thanks.




glad it worked