Steps for unlocking Linux user account

Connect as root and switch to <locked_user_account> and execute the below steps:

me@mordor:~> sudo /sbin/pam_tally --user frodo
User frodo    (500)   has 32

After unlocking the userID password, I was able to login with the new credentials and avoid the error message.

me@mordor:~> sudo /sbin/pam_tally --user frodo --reset
User frodo    (500)   had 32
me@mordor:~> sudo /sbin/pam_tally --user frodo
User frodo    (500)   has 0