Current questions and answers regarding the map editor.

I placed chasms (those hidden in the editor) on the map in the Dungeon. I encountered the following bug:
If a player reveals the fog of war over even a small part of the chasm, and then saves and loads the game, instead of the chasm, the landscape of the upper level of the map is duplicated – rivers, soil types, irregularities, and so on – all of this is displayed instead of the chasms. This doesn't happen until the fog of war over them is revealed.
I've seen chasms on many maps – has anyone else encountered this?