Old thread but this does upset me when I see this. It's not a bug. It's usually just bad Revit practices by people who may not know Revit very well or don't understand Levels and views and View Range.
Typically it's because someone duplicates a view of a 1st floor plan, then adjusts the view range to see the 2nd floor. Then they wonder when they place some beams or a floor why they can't see what they've placed. Well, it's out of the view range, on the other level.
Always go to the level you want to work on, then duplicate THAT view and start working. That's why we leave original levels as Working levels that do not get renamed or put on sheets. That's where people should go to make their new views.
Personally, I'm looking for a way to discover what views in a Revit model have this going on. Schedules don't cut it. The Model Checker doesn't do it. That's how I stumbled across this thread.