I am trying to build a mechanism on a shale tile but I am getting a too close to edge error. The issue is that I had built this mechanism in this exact spot previously. It was attached to the roller besides it with a vertical pole going up to a gear attached to the windmill. I then dug out the ground above the windmills causing a cave-in. The mechanism was destroyed and now the game sees that one specific space as map edge. I can no longer build the mechanism where it was before. I can build in nearly every other space around it.