A question came up on why material tags weren’t working on this upgraded file from Revit 2012 to Revit 2013, the problem wasn’t in an upgrade it was in the Visual Style assigned to the view.  Certain commands inside of Revit don’t like the view to be in wireframe.  In this case the we were dealing with material tags, other tags such as spot elevations also don’t like wireframe.  Once a view is changed to wireframe the surface of all elements cease to exist and only the bounding edges are there.  If there isn’t a surface to tag there can’t be any materials on that surface, so tools like material tags don’t have anything to tag.  This is similar to spot elevations, however a spot elevation can see the edge of an element and tag that.