FabioLolix [1] filed a deletion request for ambiance-rw [2]:

Developer have no interest in making new versioned archives, hosted only at gnome-look.org, use the newly created ambiance-rw-git instead

[1] https://aur.archlinux.org/account/FabioLolix/ [2] https://aur.archlinux.org/pkgbase/ambiance-rw/