Originally Posted by mansour
It seems so.
The History feature and history command are not working. And the /etc/sudoers file isn't producing the outcome I expect from it after I modify it.
(add a new user or command to it) ...
Well, this is a possible clue as to the source of the error messages you are getting.
Can you post, in as much detail as possible, exactly what modifications you have made to the /etc/sudoers file?
Where you following a tutorial for editing the /etc/sudoers file? If so, can you post a link to it?
Where you getting these errors before you modified the /etc/sudoers file??
Have you tried removing the modifications that you have made to the /etc/sudoers file, and restoring the file to it's pristine, unedited state? Do these errors disappear after you remove these modifications???
It is always a good practice to backup any system configuration files before you edit them.
Here is a tutorial that may help you to restore the /etc/sudoers file if you need it: http://psychocats.net/ubuntu/fixsudo