Missing [Seat:*] in LightDM configuration for manual login.

[Viktoria Nemkin]

On this page: https://help.ubuntu.com/lts/serverguide/sssd-ad.html.en

Under this header: https://help.ubuntu.com/lts/serverguide/sssd-ad.html.en#sssd-ad-desktop

To set up the greeter screen the /etc/lightdm/lightdm.conf.d/50-unity-greeter.conf file has to look like this:

[Seat:*]
greeter-show-manual-login=true
greeter-hide-users=true

And not like this:

greeter-show-manual-login=true
greeter-hide-users=true

So the [Seat:*] line is missing from the documentation.

I've tried this on Ubuntu Mate 18.04.1 LTS.