So we had a very ugly crash bug in LXSession 0.4.6, that is fixed but we know that the fix is not complete and there will be a proper 0.4.7 release as soon as possible. This version is at least usable.
Get the file at sourceforge.net: lxsession-0.4.6.1.tar.gz, sha1: ef7f74617f7555f3e292b670099ef44389a9a849
82e5901 Fix crash on start