I have been seamlessly importing dxf files all year with illustrator and for some reason it all of the sudden won't work. It just gives me a message saying it is an unknown format and can't be opened. The dxf file is just a flattened surface exported from rhino 3d, it won't open any of my old dxf files either. They open on other computers but not on mine for some reason. I just updated to see if that would fix anything and it didn't, does anyone know why it decided to stop working?