This looks related: Jun 10 03:05:47 hostname sudo[3855]: pam_unix(sudo:auth): auth could not identify password for [username]
Double-check the entry for your user account in /etc/passwd and /etc/shadow. Thanks ** Information type changed from Private Security to Public Security ** Changed in: sudo (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to sudo in Ubuntu. https://bugs.launchpad.net/bugs/1591129 Title: password is frequently rejected Status in sudo package in Ubuntu: Incomplete Bug description: I have described this bug at https://bugs.launchpad.net/bugs/1590719 ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: sudo 1.8.16-0ubuntu1.1 ProcVersionSignature: Ubuntu 4.4.0-24.43-generic 4.4.10 Uname: Linux 4.4.0-24-generic x86_64 NonfreeKernelModules: nvidia_uvm nvidia ApportVersion: 2.20.1-0ubuntu2.1 Architecture: amd64 CurrentDesktop: Unity Date: Fri Jun 10 03:16:53 2016 InstallationDate: Installed on 2016-01-26 (135 days ago) InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021) ProcEnviron: LANGUAGE=en_US PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: sudo UpgradeStatus: No upgrade log present (probably fresh install) VisudoCheck: /etc/sudoers: parsed OK /etc/sudoers.d/README: parsed OK modified.conffile..etc.sudoers: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers'] modified.conffile..etc.sudoers.d.README: [inaccessible: [Errno 13] Permission denied: '/etc/sudoers.d/README'] To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/1591129/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp