environs

Hi - I am using an old Chief (11) and wondering if that has anything to do with my inability to export my plan to a dwg. it keeps saving as .plan.... it says it is being saved as .dwg or .dxf but when I go to find the file it is a .plan. I am trying ot send the file to a designer who works in Revit and they cannot open it.. Any ideas? I have attached screenshots of what my process looks like.