Section "InputClass"
    Identifier "libinput touchpad catchall"
        MatchIsTouchpad "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"
        Option "NaturalScrolling" "off"
        Option "MiddleEmulation" "on"
        Option "Tapping" "on"
        Option "DisableWhileTyping" "on"
        Option "PalmDetection" "True"
EndSection

gksudo gedit /etc/lightdm/lightdm.conf

[SeatDefaults]
user-session=ubuntu

ls -al /etc/alternatives/*plymouth*
sudo update-alternatives --config default.plymouth
sudo update-alternatives --config text.plymouth

sudo apt remove xserver-xorg-input-libinput