Hi Guys,
Thank your for your answers. I tried to open my dwg and dxf file in the way Klaus suggested. Unfortunately I was given the same error messages all cases even if I tried different kind file format. I attempted with the followings: Autocad 2013/2010 dwg, Autocad 2010 dwg LT, Autocad 2013/2010 dxf, Autocad 2010 dxf LT.
I attached 2 files, 1 dwg and 1 dxf for checking. All drawings containing the same two primitive solid objects as you can see on the picture below. (1 box and 1 sphere ) All of my files were made AUTOCAD 2013 program.
BR
Franco
Thanks for the update Franco.
At last the penny has dropped, my requirements are to handle 2D DXF Files for non CAD manipulation. I am very pleased to hear you have resolved your problem.