Today, after installing a desktop extension, the system crashed and back to the login interface. After entering the password, the screen splash and back to the login interface again. Restarting the computer does not fix the problem. I found many tutorials on the Internet, including modifying the permissions of Xauthority, which is not suitable for my situation. Later, I found an effective solution and take this as a note.
Desktop environment: GNOME3
First of all, make sure it is caused by the installation of the wrong extension. I could determine that because the interface stuck and crash when I was trying to install an extension. If it is caused by other reasons, please find a solution based on your own problems, this solution may not be effective.
ctrl + alt+ f2 in the login interface to switch to the terminal.
type your username and password, and locate to the folder where gnome3 stores extensions.
backup your extensions
mv extensions extensions_bak
create a new extensions folder
then quit terminal or simply press
ctrl + alt + f1
now try to login with GUI, and it will be fine.
After login successfully, locate to that folder and remove the extension that causes the system crash, and move the rest of your extensions back to
extensions. Re-login your system and done!