Use the old editor, make a circle with the outline and inside colors different, save the image, put it in the new editor (if it doesn't work make the image two frames), and zoom in on the outline, and you got your gradient.

ok so you draw a circle with thick lines, of a color you want. then you fill it in with another color you want. download the file, and load it into the new editor, zoom in where the colors meet. When you load the color into the new editor and the middle isn't colored, redownload the file and then place it again and it should be fine