I was playing the career scenario and got to the point where I had to build a second coaster. I could not find a decent area because it kept yelling me that it intersected the terrain. So, I leveled the terrain only to find that the trees and rocks in that area ended up floating in the air. it was just at that time the autosave kicked in making a save with the trees in the air. I tried the ctrl +z sequence but it would not let me go back far enough to make a correction. I tried to move or delete the floating objects only to find I could not do it since they were built into the scenario at the start. I would like it if Frontier would change this and allow us to edit such things. I also found this type of thing when finishing the Arrow coaster where tree branches would smack the riders in the face as they exit the lift hill and these trees can't be edited either. When I test coasters etc I always use the first person ride camera to make sure there are no obstacles in the way.