Certainly, you are right Ross.In fact the error could be limited to rasp os. I did omit this important point in my report !
I did solve the problem by installing dbus-x11. So now dbus is started. I cannot retrieve the exact words but the message was about : Enlightenment does not start because dbus is not started.I start it when the error existed and now too, by filling .xinitrc and manual startx after manual login.
