When I try to make a new area, all I get is a series of green lines where the default grass should be. Similar effects occur on any objects I try to place or preview. What should I do?

Sorry for bumping my thread, but I felt that I should give an image, to show what I'm talking about. This is what the display looks like when I try to make an area.

Long time since last time I used the NWN2 toolset, but that image is the layout of the level (the mesh skeleton the other players need to download).

If I remember well, there should be an option to disable that view.

Check your view options (top bar). Toggle things like grid/mesh/wireframe

I did what you said, and got it fixed.

Thank you!