We ran into two interesting View Range problems today.
Interior elevation tags from the first floor plan were mysteriously showing up on the second floor plan. That's because if the top of the crop region for an interior elevation view intersects the primary range (bottom clip plane) of the floor plan above, then the interior elevation symbol will show in the floor plan above. So you have to either lower the top of the interior elevation's crop region or you have to raise the bottom clip plane of the primary range in the floor plan above. Thanks to Steve Valenta on AUGI for pinpointing the exact solution.
While in the second floor plan we underlayed the 1st floor plan but the 1st floor plan walls were not visible while doors, windows, and fixtures were. That's because if the top of the wall below intersects the primary range (bottom clip plane) of the floor plan above, then Revit won't include the walls in the underlay. So we had to raise the bottom clip plane which shouldn't have been below the floor level anyway.