[Inkscape-user] .dxf files

I have robocraft. I was told that inkscape would save files as .dxf extensions which robocraft uses. I saved the files as .dxf, but when I go to open it in the robocraft software it says that there was an error in the file. I tried exporting it as well with no luck. Can someone tell me what I am doing wrong?

Thanks, Jenny