As discussed in https://forum.freecadweb.org/viewtopic.php?f=3&t=54842, if OpenSCAD creates a DXF with no layers in it, the code that is supposed to handle that in FreeCAD has a minor type error in it that prevents the import from working.
As discussed in https://forum.freecadweb.org/viewtopic.php?f=3&t=54842, if OpenSCAD creates a DXF with no layers in it, the code that is supposed to handle that in FreeCAD has a minor type error in it that prevents the import from working.