Lxsession-edit program in lxsession sources does not work - it exits immediately, even doesn't attempt to show any window, and doesn't print any message to give a clue what is the problem. Session type is Openbox with LXDE, not lxsession. The lxsession-edit version 0.2.0 works just fine. Thank you.
Could you try again from git ? I just test it under openbox session, and it's working.