This is surely going to be explained at a later stage in the Tutorial, but it's curious how copying all the objects in LokirsTomb and paste replacing them in say, a duplicate of AAAmarkers removes the ambient light in the dungeons, and produces a grey void.

Or does this indicate a http://www.creationkit.com/Talk:Bethesda_Tutorial_Traps_and_Prefabs#Ambush:_Draugr_Not_Spawning_in_Coffin with the objects copied?