I installed Ubuntu 18.04, then continued with installing the software I need, then continued with changing some settings, then the screen froze, I had to shut the computer off with the power button. After that the computer booted fine until the login screen, whereafter a successful login a dark red screen is shown, the mouse cursor is shown and I can move it, but nothing else happens. The desktop is not shown.
The setting that I changed when it froze had something to do with indicator applets if I remember correctly, I just switched it from off to on and then the computer froze.
I have no idea how to debug or fix this. Any ideas, please?
Update The settings I changed were to show the day of week in the clock, and set lock screen to 3 minutes, change background image to the standard ubuntu image showing a mountain range. After that I toggled the indicator applets from off to on and then the computer froze instantly, it did not even update the toggle image of the switch to on before it froze. All settings were changed through the settings GUI.
sudo adduser mytestuser) and try to log into the account with a graphical session.