Parapets still unreachable (top of stairs) although path from other side exists

Build a way to them but message persists, nobles can get there (see screen) but when i rightclick-assign i get "cannot reach"- messaging. Save attached.

Edit: So yea, nobles can definitely navigate there themselves (new screenshot attached, damn, should have teared that down xD)

The Wallow Zombies.Save 70.octsav.gz