Dumping SP 1200 Floppies with the HxC software itself doesn´t work.
Dumping SP1200 Floppies with the KryoFlux works pretty well and really fast and comfortable and can be done on a PC and on MAC as well.The generated images must be converted into .hfe-images later with the HxC Software.
That´s the way I went with it:
(I´m just familiar with the GUI and work on a Mac)
Open up your Kryoflux GUI. goto file-settings and select the "EMU II sector image" , chose your target folder. Now comes the important part.
you´ll need to exchange the extension "img" in the extension field in the menue-settings through "emuiifd" (thanks to jeff for the instruction) . Otherwise batchconverter of HxC won´t work here.
Press ok and then enter the name of your image in the controlwindow. Also choose "emu II sector image" here.
Put in your SP 1200 floppy and start converting.
When finished, open the HxC software and select "batchconvert", enter source and target folder and start converting.
Copy the converted .hfe-files onto your SD card and try to load up one of the files into your SP 1200
With me, it worked great. hope this helps

peace, 12bitski