Authentication Token Manipulation Error

You may get an error, such as Authentication Token Manipulation Error, while trying to change passwords for a user. For example:
#passwd user

Authentication Token Manipulation Error

This error is being produced because you are using shadowed password files and the shadow doesn’t have entry for this user. i.e, /etc/passwd has an entry for this user, but /etc/shadow doesn’t.

In order to resolve this, you can either add the entry manually or recreate the shadow file. You can use pwconv to recreate the shadow file.