Hello,
thank you very much for your fast reply.
First, I tried your hints I found on an other post. Clouds shadows change quite much with texture setting max or middle. To know that saves a lot of time not trying to tweak. Have you written this in the manual? Should be.
White clouds. I could reproduce it and it was due the moon. Thank you. solved.
Skymaxx is a great add on. Thank you for that.
cheers