Looking for logging into the Lightdm Black Multiple Monitors site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Lightdm Black Multiple Monitors site. After that you can login as usual with your login credentials.
https://askubuntu.com/questions/234930/choose-lightdm-login-screen-location-in-multi-monitor-setup
https://ubuntuforums.org/showthread.php?t=2221038
https://forum.xfce.org/viewtopic.php?id=9878
https://bugs.launchpad.net/bugs/813566
https://bugs.launchpad.net/bugs/1426664
https://forum.antergos.com/topic/6366/login-screen-on-wrong-monitor
https://github.com/Antergos/web-greeter/issues/49
https://wiki.archlinux.org/index.php/LightDM
http://www.sudo-juice.com/lightdm-resolution/
https://www.reddit.com/r/archlinux/comments/4uxw9r/lightdm_black_screen/
https://www.reddit.com/r/archlinux/comments/3o3gxk/lightdm_after_suspend_i_login_black_screen/
https://stackoverflow.com/questions/52837824/setting-dualhead-background-with-lightdm-gtk-greeter
https://unix.stackexchange.com/questions/tagged/lightdm