Thank you clsn I actually tried that. I thought maybe painting red the whole model it would do the trick. But it didn't Was it supposed to? J
As I understand it, the Shapeways Tools script *assigns* weight paint to the vertices so you can see where it's having trouble. So places that are red, the script thought were too thin for walls (places that are okay are in blue, or at least green). Repainting with weight paint won't make any difference, since the point is that the *shape* is bad (too thin) and to fix it you have to fix the shape (make it thicker, or shorter, or whatever). On the other hand, the script's decision isn't final either. It can't necessarily tell what will be considered a detail and not a wall, and it's sometimes wrong. Don't take it to be authoritative; you can upload things even if the script doesn't like them.