Why sudo command is not working on my fresh debian installation.I had this error after entering my root password:Sorry try again ..or / andincorrect password attemptEDIT : In my /etc/sudoers, I have the default content :## This file MUST be edited with the 'visudo' command as root.## Please consider adding local content in /etc/sudoers.d/ instead of# directly modifying this file.## See the man page for details on how to write a sudoers file.#Defaults    env_resetDefaults    mail_badpassDefaults    secure_path=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin# Host alias specification# User alias specification# Cmnd alias specification# User privilege specificationroot    ALL=(ALL:ALL) ALLmyuser ALL=(ALL:ALL) ALL# Allow members of group sudo to execute any command%sudo   ALL=(ALL:ALL) ALL# See sudoers(5) for more information on #include directives:#includedir /etc/sudoers.dI am sure that I am typing the right password.Update:When the system locks the screen, I can't log in. This is the auth log:polkitd(authority=local): Unregistered Authentication Agent for unix-session:/org/freedesktop/ConsoleKit/Session8 (system bus name :1.124, object path /org/gnome/PolicyKit1/AuthenticationAgent, locale en_US.UTF-8) (disconnected from bus)
sudo not working on debian
debian;sudo;users;root