You've probably chose to keep your current configuration file (/etc/lightdm/lightdm.conf) on LightDM upgrade. If it's so, comment/erase these lines there:
greeter-session=lightdm-greeter session-wrapper=/etc/X11/Xsession
You've probably chose to keep your current configuration file (/etc/lightdm/ lightdm. conf) on LightDM upgrade.
If it's so, comment/erase these lines there:
greeter- session= lightdm- greeter wrapper= /etc/X11/ Xsession
session-