I'm generating my own DXF files to be loaded with AutoCAD and other CAD systems. My files load fine with the CAD systems I've tested, including AutoCAD R14, but when I try to load it with R15, it chokes on the ELLIPSE with the error "Undefined group code 10." I've tried everything I can think of to get the to work, but am at a loss. The file is about 20,000 lines. If I delete the 38 lines that contain the only Ellipse in the file, it loads into R15 fine. But if I leave it in, I get the error. Below are the 38 lines. If someone could clue me in, I'd be indebted. Thanks! Rich 0 ELLIPSE 5 256 100 AcDbEntity 8 1_MISC 100 AcDbEllipse 39 0 62 2 10 550.798950 20 709.608337 30 0.0 11 0.750000 21 0.000000 31 0.0 210 0.0 220 0.0 230 1.0 40 0.833333 41 0.000000 42 6.283185