I have been an HVAC Mechanical Drafter for years, using AutoCAD ABS/MEP products and now I'm venturing into the world of Revit. I linked a floorplan from an architect and I went to copy the 1st floor in to copy the rooms in for my HVAC Loads, running diffuser, ect. This is the error it gives me. Can anyone point me into the right direction on why this is happening, and what should I be doing about this? Thanks in advance.