You try to login to your graphical environment under linux, but the screen remains black and nothing more happens.
It does not matter if you have a vanilla (brand new) account (without any profile folders) or an account with an old KDE/Plasma profile in it. In Debian Stretch (and maybe also in Debian Buster) there is a bug which prevents the proper first start of Plasma. To circumvent this problem you have to stop the current session and then login again.
Press CTRL-ALT-F1 to switch to the console.
- Login with your credentials
use loginctl list-sessions to check the running sessions. If you have just login through Plasma and have opened a console you should see two sessions. The session under tty1 is the console one, the other one is the Plasma Session:
$ loginctl list-sessions SESSION UID USER SEAT TTY 3 16320 username seat0 49 16320 username seat0 /dev/tty1 2 sessions listed.
Now you can kill the hanging session (in the above example the first one with SESSION ID 3) with loginctl terminate-session 3
- After the Login Manager has restored, login again.