This was due to a MIME issue, which has now been resolved with help from a GNOME developer, for which I am very grateful.
** Changed in: gnome-control-center (Ubuntu) Status: Incomplete => Invalid -- gnome-appearance-properties will only allow me to choose between the default wallpapers https://bugs.launchpad.net/bugs/263342 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is a bug assignee. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs