Authentication loop/lockout after attempting to enable fingerprint on Zorin OS

General Help
1

Hi everyone,

I followed the official Zorin OS instructions to enable my fingerprint reader, but I am now locked out of my administrative privileges.

What I did:

  1. I opened the terminal and ran: sudo pam-auth-update.
  2. I enabled the "Fingerprint authentication" option as instructed.
  3. I rebooted my computer.

Now I'm stuck in a loop:

-Every time I try to run a command like sudo pam-auth-update again, I get "Sorry, try again" and "3 incorrect attempts" instantly without even typing.
-When I log out, the login screen fails to prompt for a password properly, forcing me to reboot just to get back into my session.
-I cannot use the "Unlock" button in Settings > Users. It fails immediately without letting me type my password.

Thanks in advance for your help!

2

Did a websearch using search term "sudo pam-auth-update loop Ubuntu 24.04" (as Z18 is based on Ubuntu 24.04).
Found this, which may help: https://askubuntu.com/questions/1525388/help-with-user-authentication-after-upgrading-to-24-04-1

3

Update: SOLVED!

I finally figured out the root cause. It wasn't a keyboard layout issue after all. The problem started when I enabled the Fingerprint Reader. I accidentally checked an extra option/box during the setup which completely locked me out of the login screen (looping or refusing connection).

Here is how I regained access:

  1. I booted into Recovery Mode (via the GRUB menu).
  2. I selected Drop to root shell prompt".
  3. I mounted the file system with write permissions: mount -o remount,rw /
  4. I reset my password manually using the command: passwd my_username.
  5. After a reboot, this allowed me to bypass the broken fingerprint login loop and get back into my desktop to fix the settings.

If you are stuck after messing with fingerprint settings, the root shell is the way out!

Thank you for your help @zabadabadoo :wink:

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