All of my Ubuntu 18.04 LTS installations eventually gets stuck in a loop where the screen shows the last user who logged in and is prompting for a password.
It has the following options:
Cancel, Unlock, Log in as another user, and Entering the password.
The user can't enter the password because he doesn't know the other user's password. The power button at the top right only has the option to put the machine to sleep. It doesn't have the option to reboot.
I'm aware that someone can use the Ctrl+Alt+F# hotkey to switch consoles. However, this has many people locked out of the computer unless they perform a hard reboot.
Does anyone know what can be done to stop this loop from happening?