Change Login Screen Background

[joesplace]

On Ubuntu Mate 21.10 is there any easy way to change the login screen background?

[jymm]

Adminstration>Login Window (enter password) click on backgrounds box, navigate to the background you want and set it. Personally I put the .jpeg or .png I want in usr/share/backgrounds.

[joesplace]

As you can see from the pic below, there is no Login Window app in the Administration section of 21.10 MATE.

[joesplace]

Found a way in a previous post:

@Utsuro

Basically, you need to edit a file with the path to your desired background and then run another command.
To do so, in a terminal, enter:
sudo pluma /usr/share/glib-2.0/schemas/30_ubuntu-mate.gschema.override
and edit line 2 (background='/usr/share/backgrounds/ubuntu-mate-common/Green-Wall-Logo.png') , replacing the path with the one to your wallpaper and save the changes. Don't screw up or it could cause trouble.
Then in a terminal:
sudo glib-compile-schemas /usr/share/glib-2.0/schemas/
And that's it.