the weird thing is this, before I went to try the Cscatter, I did some render study for the tree if everything will work out. It's fine. I render 1 tree from Laubwerk with a corona sun. Looks good. And I did the scatter thing from the youtube tutorial. Looking good from the start, but like what I said earlier, when I tried to do the scatter in grass, it crash. The crash thing is not the problem, the problem is when I tried it again for another scene, it became like the second picture above. I didnt touch anything in materials. I just drag tree from Laubwerk panel, add sun and render. That's it. I dont know why?