CAM software not recognising exported DXF file

I exported a very simple file in DXF format. However my CAM software says the file is empty, or contains items it can’t read (see first screenshot).
However, if I export the same file to Sketchup, and re-export it as a DXF file, it imports without issue. Any idea what’s going on?

Could you share the DXF file here or with our Support team? We could look into it and hopefully figure out what’s going on.

The forum won’t allow me to upload a DXF file…

Thanks. Will do.