I'm building my website / application where users can upload and/or customize existing drawings to fit their own needs and dimensions. It all worked with SVG, but now I'm working on a DXF export, so I can send drawings to cnc routers. I do have one program (viacad) which is showing my dxf drawings correctly. However I did send a few of my drawings to a cnc / carpenter shop who could not read my generated (attached boomerang.dxf) file with autocad 2010 ( internal error: !dbr12dxfin.cpp@2318 ) after which autocad crashed and tried to send a report to autodesk. I'd really appreciate if somebody could give me hints on what's wrong. You can experiment yourself with my online dxf generation tool select DXF (You need a modern non IE browser, firefox v10 or chrome v16 are just fine) and provide feedback on the generated dxf.