Comment 3 for bug 1390060

Note from your bootlog that you have some apparmor policy errors: https://launchpadlibrarian.net/189391868/BootLog.txt

Your /etc/apparmor.d/tunables/home file should be owned by root with group root and permissions 0644.

You may need to customize the contents some, here's mine:

# ------------------------------------------------------------------
#
# Copyright (C) 2006-2009 Novell/SUSE
# Copyright (C) 2010 Canonical Ltd.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of version 2 of the GNU General Public
# License published by the Free Software Foundation.
#
# ------------------------------------------------------------------

# @{HOME} is a space-separated list of all user home directories. While
# it doesn't refer to a specific home directory (AppArmor doesn't
# enforce discretionary access controls) it can be used as if it did
# refer to a specific home directory
@{HOME}=@{HOMEDIRS}/*/ /root/

# @{HOMEDIRS} is a space-separated list of where user home directories
# are stored, for programs that must enumerate all home directories on a
# system.
@{HOMEDIRS}=/home/

# Also, include files in tunables/home.d for site-specific adjustments to
# @{HOMEDIRS}.
#include <tunables/home.d>