I am new to DesktopX. I am using a theme called Fusion.
I change the default wallpaper by
1)right click-->settings-->display properties
2)switch on DesktopX builder-->configure DesktopX builder-->desktop-->wallpaper
3)edit the wallpaper file in the theme file
After changing the wallpaper, I cannot save properly. So when I restart the theme, the original wallpaper appears. The wallpaper I have changed is

Is there a particular way to change wallpaper??