... try placing a wmo and save every single ADT it is somehow involved with ? Karazhan is quite large - try saving a 4x4 ADT raster (where the WMO is one AND the surrounding ones).
Else you have to be careful what Karazhan you use. The tower is solid on the outside, but it becomes empty the further you go in (it's just for show, after all). The instance has no visuals outside (no actual outside tower), but it uses the complete instance inside (duh).
