I have saved a .dwg file that I'm using on my AutoCAD 2011 as an earlier version of AutoCAD (2007) and sent it to a friend who has 2009 version. She is getting an error message saying that the drawing is invalid. We tried using the .bak file and recovering the file and even inserting it in an open dwg. none of which works. I even sent her a .dxf file but it still doesn't work.
I thought maybe it's because everytime I save a file AutoCAD generates a .dwxf file along with the dwg. so I sent her that file too but she still can't open the file.
Any idea what it might be ?!!