Comment 6 for bug 577563

From duplicate bug #581303:

You cannot automatically login or do a passwordless login if your home directory is encrypted. When you switch to the terminal and log in, you're decrypting your home directory. Thus, once you've logged in through the terminal, you can log in to your desktop by going back to the login screen through "ctrl+alt+F8" or a "sudo service gdm restart".

I went to "Users and Groups" and selected "Don't ask for password on login". When "Login Screen Settings" wouldn't let me log in automatically (my username was not selectable), I assumed it was a bug, not a warning, so I manually edited the /etc/gdm/custom.conf file to let me log in automatically. Because I still wanted my computer to be (mostly) secure, I enabled the lock screen after login. But when gdm tried to automatically log in, the screen would go blank and then I would be kicked back to the login screen because my home directory was encrypted.