Xfce 4.12 on Fedora 22 (alpha) does not display icons for appfinder and "run program" (xfce4-appfinder --collapsed), I believe, due to changes in GTK. The "offending" issues are in the desktop files - xfce4-appfinder.desktop xfce4-run.desktop corresponding to lines Icon=gtk-find Icon=gtk-execute respectively. The lines below _should_ fix the issue. sed -i 's/gtk-find/edit-find/g' data/xfce4-appfinder.desktop.in sed -i 's/gtk-execute/system-run/g' data/xfce4-run.desktop.in
This was addressed in: https://git.xfce.org/xfce/xfce4-appfinder/commit/?id=4f3266b4902cc983385fbe6fee0a26db1002dcfb