How to fix the error is not logged in Ubuntu

One of the most common and controversial errors that Ubuntu users encounter is when trying to log in to Ubuntu after booting, you will be taken back to the login screen and the process of infinite iteration. This error is called the Login boot loop.

It is so awful! But don't worry, there are a few ways to break this loop. The most common cause is an unusual licensing issue with the file Ubuntu needs to launch the graphical interface. You can fix this yourself by opening the shell command line tool and editing permissions for that file. This approach is quick and effective in most cases.

Log in to Shell

Start Ubuntu as usual. When going to the login screen, do not log in to Ubuntu. Instead, press Ctrl + Alt + F3 on the keyboard. Ubuntu will exit the graphical login screen and go to the terminal.

Enter the user name at the command prompt, then provide the password when requested. You will come to a familiar terminal screen. Here, use navigation arrows as you normally would in a terminal.

Check the rights of Xauthority

The file to check is in the root of the directory '/ home'. After logging in, you will be in this directory. This file is a 'hidden' file, so it will need to use the correct flags when searching. Search by using ls and grep in the following command:

 ls -lah | grep -i Xauthority 

You will see the file listed with the rights first, followed by the username and the group that owns it. If you see 'root' listed there, that's the source of the problem.

Change the rights of Xauthority

Now you know what caused the problem. It's time to fix it. Instead of root, users and groups should have ownership of that Xauthority file. You can change ownership by running the chown command with sudo.

 sudo chown username:username .Xauthority 

After running this command, try logging in again. Press Ctrl + Alt + F7 to return to the normal login screen. Please login to Ubuntu!

Other options

If the above doesn't work or the Xresource file is owned by the average user, there are still a few other options to try. There is no guarantee that these ways will work, but still worth a try, right?

Change permissions '/ tmp'

Sometimes, the '/ tmp' directory, which stores the temporary files that the computer is working on, encounters the same problem as the Xauthority folder. The process of repairing these 2 directories is very similar.

Log in to the terminal again. Then check the permissions of '/ tmp'.

 sudo ls -lah /tmp 

You can see the permissions for the directory entered at the beginning. If it looks like drwxrwxrwt, everything is fine. If not, you should reset them to that state with chmod and sudo.

 sudo chmod 1777 /tmp 

Change Display Manager

Finally, when all other options don't work, you can try switching your Display Manager. Problems often appear in previous versions of Ubuntu 17.10, when switching to Gnome and GDM to login. However, on some versions of Ubuntu, LightDM is still considered standard. If you're using Gnome and GDM, you can try LightDM. Log in to the terminal again, install Display Manager you want to try. During the installation process, Ubuntu will ask if you want to convert. Please agree with this conversion!

If you're lucky, one of these methods will solve the problem and you can log in to Ubuntu as usual.

Good luck!

See more:

1. How to troubleshoot Ubuntu problems does not start
2. Enable Root account in Ubuntu
3. How to run and install Pantheon Desktop on Ubuntu