I'm using the new gridmap as a basis for a new map, and I've managed to delete everything except the skycurves. Every time I delete them and save the level, next time I open it, there they are. Which json do they live in? Are they part of a forest object I can't find?
The mainLevel.lua file loads the skycurve from Track Builder or something like that. Get rid of it or at least delete the skycurve section in it.