If you get the following error when trying to login to an account on a Linux OS the likelihood is that the account has been locked out / expired:

Your account has expired; please contact your system administrator

To re-enable an expired Unix account that has been locked out due to a timer you can run the following command via root or sudo user:

sudo chage -E -1 <username>

It may also be the case that the user is blocked by pam_tally. To list pam_tally blocked users you can run the following:

pam_tally2 --user example_user

To unlock an account / reset counter for failed login attempts we can run the following:

pam_tally2 --user example_user --reset