Black screen after boot with Kali 2.0

[Ogloppi]

I installed Kali 2.0 light to 16GB USB stick with persistence and I could reboot the installation just fine straight into XFCE desktop. I ran update, upgrade and dist-upgrade and rebooted. After boot I can see a completely black screen with a mouse cursor that I can move around. Shutdown dialog also shows up if I press the power button. I can press Ctrl + Alt + F2 and get the command line prompt to manually login with root/toor. After that I can start the desktop with "startx" and everything seems to work normally.

Why Kali doesn't boot straight into desktop anymore?
And what log files would provide any hints to this?

Currently using the USB stick on HP Compaq 6715s laptop.

/var/log/auth.log

Oct 10 08:34:48 localhost usermod[1007]: change user 'root' password
Oct 10 08:34:48 localhost systemd-logind[1309]: Watching system buttons on /dev/input/event3 (Power Button)
Oct 10 08:34:48 localhost systemd-logind[1309]: Watching system buttons on /dev/input/event4 (Video Bus)
Oct 10 08:34:48 localhost systemd-logind[1309]: Watching system buttons on /dev/input/event2 (Lid Switch)
Oct 10 08:34:48 localhost systemd-logind[1309]: Watching system buttons on /dev/input/event1 (Sleep Button)
Oct 10 08:34:48 localhost systemd-logind[1309]: New seat seat0.
Oct 10 08:35:04 localhost lightdm: pam_unix(lightdm-autologin:session): session opened for user root by (uid=0)
Oct 10 08:35:04 localhost systemd-logind[1309]: New session 1 of user root.
Oct 10 08:35:04 localhost systemd: pam_unix(systemd-user:session): session opened for user root by (uid=0)
Oct 10 08:35:12 localhost polkitd(authority=local): Registered Authentication Agent for unix-session:1 (system bus name :1.16 [/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1], object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8)
Oct 10 08:35:12 localhost pkexec: pam_unix(polkit-1:session): session opened for user root by (uid=0)
Oct 10 08:35:12 localhost pkexec[1517]: root: Executing command [USER=root] [TTY=unknown] [CWD=/] [COMMAND=/usr/sbin/xfpm-power-backlight-helper --set-brightness-switch 0]
Oct 10 08:35:16 localhost login[1526]: pam_unix(login:session): session opened for user root by LOGIN(uid=0)
Oct 10 08:35:16 localhost systemd-logind[1309]: New session 2 of user root.
Oct 10 08:35:16 localhost login[1531]: ROOT LOGIN  on '/dev/tty2'
Oct 10 08:35:22 localhost polkitd(authority=local): Registered Authentication Agent for unix-session:2 (system bus name :1.26 [/usr/lib/policykit-1-gnome/polkit-gnome-authentication-agent-1], object path /org/gnome/PolicyKit1/AuthenticationAgent, locale )
Oct 10 08:35:23 localhost pkexec: pam_unix(polkit-1:session): session opened for user root by (uid=0)
Oct 10 08:35:23 localhost pkexec[1691]: root: Executing command [USER=root] [TTY=unknown] [CWD=/] [COMMAND=/usr/sbin/xfpm-power-backlight-helper --set-brightness-switch 0]
Oct 10 08:36:40 localhost gnome-keyring-daemon[1804]: couldn't access control socket: /run/user/0/keyring/control: No such file or directory
Oct 10 09:17:01 localhost CRON[2399]: pam_unix(cron:session): session opened for user root by (uid=0)
Oct 10 09:17:01 localhost CRON[2399]: pam_unix(cron:session): session closed for user root

/var/log/syslog had a few warnings

Oct 10 08:34:49 localhost lightdm[1328]: ** (lightdm:1328): WARNING **: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files
Oct 10 08:35:04 localhost lightdm[1328]: ** (process:1368): WARNING **: Error getting user list from org.freedesktop.Accounts: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Accounts was not provided by any .service files

EDIT: The solution was surprisingly simple. Heres how to fix this:

1. When the black screen with mouse appears, press CTRL+Alt+F2 and login with root/toor.
2. Write "startx" and press Enter to get to XFCE desktop.
3. Go to XFCE menu > Settings > Session and Startup > Session tab
4. Press "Clear saved sessions", then "Close" and reboot your PC.

If any mod sees this, please update the thread title to solved.