These five fences to the left of me are nearly unbuidable if the flooring im standing on is a blueprint. If you remove some of the blue prints of the fences you can end up building some of them, but not all of them in the end. I found that the only way I can build the last fence (or any of them if I don't mess with it) is if I either delete the blue print of the flooring im on or build the flooring. By far one of the most peculier bugs I've found. (EDIT): I think I might have figured it out. When the player stands on a blueprint of the flooring, he usually refuses to build anything. He almost always tries to pathfind off of the blueprint of the flooring in order to place items into another blueprint adjacent to the flooring..