After the upgrade, you lost shortcut functions. You could not open xfrun4 by Alt+F2 key. The problem is xfce4-settings-helper could not find libxklavier.so.12. You would get this:
root@chuyen:/usr/lib# ldd /usr/bin/xfce4-settings-helper | grep found
libxklavier.so.12 => not found
Quick fix:
root@chuyen:/usr/lib# ln -s libxklavier.so.16 libxklavier.so.12