When you undo it, the steel wall (leveleditor) is invisable; if you play it,
the level is completely invisable.
The bug wears off when you exit the level or go to the next level.

And...
Still if you cut the steel wall around by a piece and undo it, the steel wall
(leveleditor) remains visble due to the undoing with the steel walls around.
BTW: I added my own avatar for myself, check it out! It's a Grunt Tediz from the Conker game.
