Why can't I change the wallpaper in Gnome Shell and Unity?
In my case, enabling
Icons on Desktop
(first option in Desktop section of the gnome-tweak-tool) did the trick.
Nautilus handles the desktop in both Unity and Gnome Shell, to make sure you have this activated do the following:
- Download Gnome Tweak Tool
sudo apt-get install gnome-tweak-tool - Open it and select Desktop then activate Have file manager handle the desktop by clicking the switch.
- Log out.