SVG basic shapes <polygon>, <polyline> not supported in DXF export

Please add information about OS/platform and Inkscape version (see Inkscape menu 'Help > About Inkscape') to the bug description.

Please also attach a test case (original SVG file, exported DXF file, SVG file saved after reopening the exported DXF file) to the bug report to allow further investigation of the reported problem.

It would also be helpful if you could list the export and import options used for the DXF file.

OS: Windwos 7
Inkscape Version: 0.91

Please find the DXF export options (German) in the screenshot attached.

Please find the DXF import options in the screenshot attached.

it appears that this drawing was originally created in Matlab, see
"Matlab Figure Converted by PLOT2SVG written by Juerg Schwizer"
For this reason it contains some elements not normally produced by Inkscape. Currently the dxf output routine does not support the SVG entities polygon or polyline, which are used in the svg file.
However, there is a workaround. In Inkscape use the menu item Edit->Select All. Then use the menu item Path->Object to Path. Then save as dxf. During the save process, I would recommend unchecking the option for RoboMaster output. This is a specialized output designed to be used only by RoboMaster software.

The result I get is attached here, and appears to contain the objects of interest.

Thank you for the answer! Indeed I created the original SVG file using PLOT2SVG by Juerg Schwizer.
Thank you as well for the workaround! May I suggest that future versions of Inkscape should support polygon and polyline entities? This would be helpful.
In the meantime I found a way to generate DXF files directly from Matlab using the Matlab DXFLib by Grzegorz Kwiatek. Nevertheless it would be fine if I could check the DXF files generated this way by displaying them in Inkscape. This does not work currently.

could you attach one of the DXF files that does not display in Inkscape?

also, if you're looking for a free dxf viewer, you could try QCad at:
http://www.ribbonsoft.com

The file attached was created in Matlab with DXFLib and is not displayed in Inkscape 0.91 - but it definitly works for a cutting plotter (proven).

Thank you for the link to QCAD! I installed it and it works to show DXF files (more precisely: it works, when the file is "opened", not when it is "imported").

thanks for the dxf file. I see that the version number $ACADVER is AC1006. This means that it is Release 10. The current dxf import routine supports only Release 13 and newer. Release 10 contains entities such as POLYLINE and VERTEX which are no longer supported.

If necessary, it is possible to upgrade the dxf file to a newer version. Open it in QCad and then save it using the default file type DXF. This will automatically convert it to Release 13 or newer. The result is attached here, and is viewable in Inkscape.