package update-notifier-common 3.168.7 failed to install/upgrade: end of file on stdin at conffile prompt

....

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: update-notifier-common 3.168.7
ProcVersionSignature: Ubuntu 4.4.0-112.135-generic 4.4.98
Uname: Linux 4.4.0-112-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Mon Jan 29 09:32:30 2018
ErrorMessage: end of file on stdin at conffile prompt
InstallationDate: Installed on 2016-11-13 (442 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.3
 apt 1.2.25
SourcePackage: update-notifier
Title: package update-notifier-common 3.168.7 failed to install/upgrade: end of file on stdin at conffile prompt
UpgradeStatus: No upgrade log present (probably fresh install)
modified.conffile..etc.apt.apt.conf.d.10periodic:
 APT::Periodic::Update-Package-Lists "1";
 APT::Periodic::Download-Upgradeable-Packages "0";
 APT::Periodic::AutocleanInterval "0";
 APT::Periodic::Unattended-Upgrade "1";
modified.conffile..etc.apt.apt.conf.d.15update-stamp: APT::Update::Post-Invoke-Success {"touch /var/lib/apt/periodic/update-success-stamp 2>/dev/null || true";};
modified.conffile..etc.apt.apt.conf.d.20archive:
 APT::Archives::MaxAge "30";
 APT::Archives::MinAge "2";
 APT::Archives::MaxSize "500";
modified.conffile..etc.apt.apt.conf.d.99update-notifier:
 DPkg::Post-Invoke {"if [ -d /var/lib/update-notifier ]; then touch /var/lib/update-notifier/dpkg-run-stamp; fi; /usr/lib/update-notifier/update-motd-updates-available 2>/dev/null || true";};
 APT::Update::Post-Invoke-Success {"/usr/lib/update-notifier/update-motd-updates-available 2>/dev/null || true";};
modified.conffile..etc.update-motd.d.90-updates-available:
 #!/bin/sh

 stamp="/var/lib/update-notifier/updates-available"

 [ ! -r "$stamp" ] || cat "$stamp"
modified.conffile..etc.update-motd.d.98-fsck-at-reboot:
 #!/bin/sh

 if [ -x /usr/lib/update-notifier/update-motd-fsck-at-reboot ]; then
     exec /usr/lib/update-notifier/update-motd-fsck-at-reboot
 fi
modified.conffile..etc.update-motd.d.98-reboot-required:
 #!/bin/sh

 if [ -x /usr/lib/update-notifier/update-motd-reboot-required ]; then
     exec /usr/lib/update-notifier/update-motd-reboot-required
 fi
mtime.conffile..etc.apt.apt.conf.d.10periodic: 2017-12-30T12:04:03.946869
mtime.conffile..etc.apt.apt.conf.d.15update-stamp: 2016-05-24T13:48:53
mtime.conffile..etc.apt.apt.conf.d.20archive: 2016-05-24T13:48:53
mtime.conffile..etc.apt.apt.conf.d.99update-notifier: 2016-05-24T13:48:53
mtime.conffile..etc.cron.daily.update-notifier-common: 2016-05-24T13:48:53
mtime.conffile..etc.cron.weekly.update-notifier-common: 2016-05-24T13:48:53
mtime.conffile..etc.update-motd.d.90-updates-available: 2016-05-24T13:48:53
mtime.conffile..etc.update-motd.d.98-fsck-at-reboot: 2016-05-24T13:48:53
mtime.conffile..etc.update-motd.d.98-reboot-required: 2016-05-24T13:48:53