How to resolve a black screen issue when switching graphics interface in Ubuntu?

Switching to a black screen when changing the graphical interface in Ubuntu is usually due to driver or configuration issues. Here are some possible solutions:

1. To restart the X Server: try pressing Ctrl + Alt + F1 to enter command line mode, then input the following command to restart the X Server.

sudo service lightdm restart

1. Check graphics card driver: Make sure your graphics card driver is correctly installed and compatible with your hardware. You can check and install graphics card drivers using the following commands:

lspci | grep VGA
sudo ubuntu-drivers devices
sudo ubuntu-drivers autoinstall

1. Check Xorg configuration: Verify that the Xorg configuration file is correct by using the following command.

cat /etc/X11/xorg.conf

1. Update your system: Make sure your system and software are up to date by using the following command to update the system:

sudo apt update
sudo apt upgrade

1. Reinstalling the graphical interface: If the methods above are not effective, you can try reinstalling the graphical interface.

sudo apt-get install --reinstall ubuntu-desktop

If none of the above methods work, it is recommended to seek help on Ubuntu’s official forum or community, or consider reinstalling the system.