Hi@all!
I changed my LOGIN_background with “lightdm-settings” but
UM 18.04 won’t applied it.
I’ll try it with/etc/lightdm/slick-greeter. conf
[Greeter]
background=/usr/share/backgrounds/ubuntu-mate-common/login01.png
logo=/usr/share/backgrounds/ubuntu-mate-common/icon.face
draw-grid=false
show-a11y=false
show-power=false
show-keyboard=false
show-clock=false
…nobody occur. Black background 
In UM 17.10 all worked perfectly. In UM 18.04 not!
lightdm-gtk-greeter.conf
[greeter]
position = 95%,end -60%,center
default-user-image = /usr/share/backgrounds/ubuntu-mate-common/icon.face
How can I add my old lightdm_settings to the new one?
Many lightdm-gtk-greeter settings are not recognized in slick greeter - it has fewer user settings. There is now a login window dialog to change the login window background.
All the same which picture I take for the background, it is not taken over. Black background.
I have already tried another path. It has no function.
In UM 17. 10 it has functioned.
I would rather have more settings.
Move the Login-Panel to the right won't work anymore 
User-avatar-picture in the Login-Panel won't show anymore
Bad things in UM 18.10.
Can I install
lightdm-gtk-greeter
lightdm-gtk-greeter-settings
in UM Mate 18.04 (Synaptic) again and use it?
Any idea how to make the option “use the user background” from the preferences work? Because enabled or not, it’ll still display the default background on my setup, not the user’s.
There was a similar issue with the LightDM greeter in UM before it switched to Slick and I made a workaround but it doesn’t seem to work anymore with Slick.
Now it works for me:
I’ve copied my backgrounds to:
/usr/share/backgrounds/ubuntu-mate-bionic
then:
(my slick-greeter.conf in /etc/lightdm)
[Greeter]
background=/usr/share/backgrounds/ubuntu-mate-bionic/background01.jpg
background-color=#00FFFF
draw-user-backgrounds=false
draw-grid=false
show-hostname=false
show-power=false
show-a11y=false
show-keyboard=false
show-clock=false
show-quit=true
logo=/usr/share/backgrounds/ubuntu-mate-common/logo.png
position=95%,end -60%,center
xft-antialias=true
xft-dpi=96
xft-hintstyle=hintslight
xft-rgba=rgb
onscreen-keyboard=false
screen-reader=false
play-ready-sound=/usr/share/sounds/ubuntu/stereo/desktop-login.ogg
enable-hidpi=false
other-monitors-logo=/usr/share/backgrounds/ubuntu-mate-bionic/background05.jpg
Logged out and my new background is set to Login-Panel.
…very strange 
how can I move the Login-Panel to the right? position=95%,end -60%,center that what I need…
Using .jpg files for Login-background.
With me, there only JPG files with Login background works.
PNG not.
