Hello. I use older versions of AutoCAD at work (14, 2002 and 2004) along with more recent versions of Autodesk TrueView (2010 & 2014).A client has sent me a .dxf file (not sure what program was used to generate it). I can open it in the viewer, however, I cannot open it in any of the full versions of AutoCAD that I have. When I try to, this error message appears in the command line:Unknown value "AC1021" encountered in drawing version.Invalid or incomplete DXF input -- drawing discarded.I can open it in TrueView, but that does me no good because I cannot manipulate it, only view it. The client even saved it in AutoCAD2007 format, with the same result.Any idea what's going on here and how to fix it? thanks in advance...

If you can open it in TrueView then can't you save it as well to a different file format like an earlier release (maybe 2000)?