First of all the script will convert existing poses to universal poses. It should ask for the folder to convert and convert all poses in that folder (if I understand all this correctly).

What you are doing is creating a universal pose, this should work by simply saving a pose. P7 should save all poses as universal poses. But beware there are issues with universal poses (see other threads) so do NOT convert your existing poses at this moment and whe saving a pose only apply it to the same figure, using it on another figure might cause problems.