In Ubuntu if you gets stuck in a login loop issue, then follow below methods to fix the Ubuntu login loop problem. This is a common issue faced by many Ubuntu users during login.
How to Fix Login Loop Issue in Ubuntu
Power on your system and in the Ubuntu login screen, don’t sign in. Instead, press Ctrl + Alt+F3 on your keyboard. It will switch into a Terminal mode. If Ctrl + Alt+F3 key wil not work then follow below all key combinations to open Ubuntu Linux in terminal mode. By default in Ubuntu linux OS, there are 7 ttys.
Note: (CTRL+ALT+F1), (CTRL+ALT+F2), (CTRL+ALT+F3), (CTRL+ALT+F4), (CTRL+ALT+F5), (CTRL+ALT+F6) and (CTRL+ALT+F7).
Now login with your username in the terminal prompt and enter the password when asked.
Run below commands one by one.
sudo apt update
sudo apt-get -y dist-upgrade
sudo apt-get -y autoremove
sudo apt-get -y clean
and try to log in again.
In the terminal screen run below command
ls -lah | grep -i Xauthority
It will show like below with your username.
If you get the result with your Username then try the next method.
If you found anything related “root” instead of your username, then run below command to change the permission.
sudo chown manikandan:manikandan .Xauthority
Here “manikandan” is my Username. You should replace “manikandan” with your Username. Press Ctrl + Alt + F7 to return to your normal login screen. and try to log in to Ubuntu again.
Reinstall Your Desktop Environment.
This is your final option. In the terminal screen run below commands one by one.
sudo apt remove ubuntu-desktop
sudo apt update
sudo apt dist-upgrade
sudo apt autoremove
sudo apt clean
After that run below command.
sudo apt install ubuntu-desktop
Now reboot using below command.
sudo shutdown -r now
In this way you can solve Ubuntu login loop problem in your system.