I found the problem , by render channels i had the alpha channel checked.
I've read on another forum that option can't be used.
So thx for your help.
grtz
i'm importing from sketchup pro6.
When i select preview viewport everything is ok, but when i render the final image the background is still black, and i have rotated the earth in the right position for the light.
When i render my desgin instead of the sky it renders a black screen, i have changed the environment settings severall times but its still the same .
Can some help me?