Thank you for taking the time to file a bug report. >From the log message above it appears you have a bad configuration option in your sshd file. I believe the option you want is 'AuthorizedKeysFile'.
Since it seems likely to me that this is a local configuration problem, rather than a bug in Ubuntu, I am marking this bug as 'Incomplete'. However, if you believe that this is really a bug in Ubuntu, then we would be grateful if you would provide a more complete description of the problem with steps to reproduce, explain why you believe this is a bug in Ubuntu rather than a problem specific to your system, and then change the bug status back to "New". For local configuration issues, you can find assistance here: http://www.ubuntu.com/support/community ** Changed in: openssh (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to openssh in Ubuntu. https://bugs.launchpad.net/bugs/1691209 Title: package openssh-server 1:7.2p2-4ubuntu2.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 Status in openssh package in Ubuntu: Incomplete Bug description: Active: failed (Result: exit-code) since Tue 2017-05-16 23:01:58 IST; 8ms ago Process: 3849 ExecStart=/usr/sbin/sshd -D $SSHD_OPTS (code=exited, status=255) Main PID: 3849 (code=exited, status=255) May 16 23:01:58 prakash-OptiPlex systemd[1]: Starting OpenBSD Secure Shell s.... May 16 23:01:58 prakash-OptiPlex sshd[3849]: /etc/ssh/sshd_config: line 2: B...e May 16 23:01:58 prakash-OptiPlex sshd[3849]: /etc/ssh/sshd_config: terminati...s May 16 23:01:58 prakash-OptiPlex systemd[1]: ssh.service: Main process exite...a May 16 23:01:58 prakash-OptiPlex systemd[1]: Failed to start OpenBSD Secure .... May 16 23:01:58 prakash-OptiPlex systemd[1]: ssh.service: Unit entered faile.... May 16 23:01:58 prakash-OptiPlex systemd[1]: ssh.service: Failed with result.... Hint: Some lines were ellipsized, use -l to show in full. ProblemType: Package DistroRelease: Ubuntu 16.04 Package: openssh-server 1:7.2p2-4ubuntu2.2 ProcVersionSignature: Ubuntu 4.4.0-77.98-generic 4.4.59 Uname: Linux 4.4.0-77-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.5 Architecture: amd64 Date: Thu May 11 12:19:31 2017 ErrorMessage: subprocess installed post-installation script returned error exit status 1 InstallationDate: Installed on 2016-01-22 (480 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) RelatedPackageVersions: dpkg 1.18.4ubuntu1.2 apt 1.2.20 SSHDConfig: Error: command ['/usr/sbin/sshd', '-T'] failed with exit code 255: /etc/ssh/sshd_config: line 2: Bad configuration option: AuthorizedKeyFile /etc/ssh/sshd_config: terminating, 1 bad configuration options SourcePackage: openssh Title: package openssh-server 1:7.2p2-4ubuntu2.2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1 UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/openssh/+bug/1691209/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp

