I am new to Ubuntu and I tried to change my login screen wallpaper by using terminal according to this:
At this time I did not know about ubuntu tweaks. However, I did not get the wallpaper and ended up with a purple dot screen as my login screen. I want to know how to revert back to my default login screen that comes when I first install ubuntu. Right now, even when I use ubuntu tweaks, it still does not update and end up with the purple dot screen. Please help!