Since Removing Samba, Winbind, Krb5 - sudo: PAM authentication error: Module is unknown - authentication

Question

I have purged a variety of packages in an effort to reinstall Samba and related DC AD from scratch.
Soon after, I receive this error at a prompt and am unable to login with my normally working local user credentials.
Fortunately, I was still logged in via SSH but even there I get the following error anytime I try to use the sudo command.
sudo: PAM authentication error: Module is unknown
Any thoughts on how to cure this? I have found another post in stackoverflow with a similar error but its resolution was of no value here.

Answer 1

This seemed to indicate a problem with the "sudo" module in /etc/pam.d/sudo but if you inspect the contents of /etc/pam.d/sudo you find there are 3 include statements in there:
#include common-auth
#include common-account
#include common-session-noninteractive
Solution:
In my case, if I restored common-account to the values found in any default Linux installation, the problem went away.
Further investigation showed me that since installing I had installed Samba, the only 4 files that changed in the /etc/pam.d/ folder since the original installation was the updated common-* files.  So I went ahead and restored those 4 common-* files to their original version from any similar Linux installation even though the problem was already solved by just restoring the common-account file.
Here is a copy of the content of common-account for Ubuntu 18.04 - 20.04 and possibly more
# /etc/pam.d/common-account - authorization settings common to all services
#
# This file is included from other service-specific PAM config files,
# and should contain a list of the authorization modules that define
# the central access policy for use on the system. The default is to
# only deny service to users whose accounts are expired in /etc/shadow.
#
# As of pam 1.0.1-6, this file is managed by pam-auth-update by default.
# To take advantage of this, it is recommended that you configure any
# local modules either before or after the default block, and use
# pam-auth-update to manage selection of other modules. See
# pam-auth-update(8) for details.
#
# here are the per-package modules (the "Primary" block)
account [success=1 new_authtok_reqd=done default=ignore] pam_unix.so
# here's the fallback if no module succeeds
account requisite pam_deny.so
# prime the stack with a positive return value if there isn't one already;
# this avoids us returning an error just because nothing sets a success code
# since the modules above will each just jump around
account required pam_permit.so
# and here are more per-package