package unattended-upgrades 0.90ubuntu0.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 128

[Adriano G. V. Esposito]

Just rebooted this evening and seen this error

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: unattended-upgrades 0.90ubuntu0.6
ProcVersionSignature: Ubuntu 4.4.0-78.99-generic 4.4.62
Uname: Linux 4.4.0-78-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.6
Architecture: amd64
Date: Tue Jun 6 20:17:09 2017
ErrorMessage: subprocess installed post-installation script returned error exit status 128
InstallationDate: Installed on 2015-10-09 (606 days ago)
InstallationMedia: Ubuntu 14.04.3 LTS "Trusty Tahr" - Beta amd64 (20150805)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.20
SourcePackage: unattended-upgrades
Title: package unattended-upgrades 0.90ubuntu0.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 128
UpgradeStatus: Upgraded to xenial on 2017-01-25 (131 days ago)
modified.conffile..etc.apt.apt.conf.d.10periodic:
 APT::Periodic::Update-Package-Lists "1";
 APT::Periodic::Download-Upgradeable-Packages "1";
 APT::Periodic::AutocleanInterval "0";
 APT::Periodic::Unattended-Upgrade "1";
mtime.conffile..etc.apt.apt.conf.d.10periodic: 2017-04-24T10:11:39.287010

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.