Stairs added to existing castle cannot be deleted and cannot be ascended

I added stairs to try out the level 2 building. I was able to lay it down, but then I could not ascend the stairs because the roofline of the castle created a blockade. So I figured I'd tear down the walls to allow for the build, but I can't dismantle it because it says it can't break path to ground, but that is not selectable to dismantle either. So now I have right angled stairs on the edge of my castle that I can't do anything with. In the picture it shows me on the stairs, but I've tried dismantling while not on the stairs.

I tore down some more structures and then I was able to dismantle and rebuild properly. This is not a bug.