package ca-certificates 20180409 failed to install/upgrade: installed ca-certificates package post-installation script subprocess returned error exit status 1

[Pham Quoc Hung]

Setting up ca-certificates (20180409) ...
Updating certificates in /etc/ssl/certs...
rehash: skipping duplicate certificate in Go_Daddy_Class_2_CA.pem
dpkg: error processing package ca-certificates (--configure):
 installed ca-certificates package post-installation script subprocess returned error exit status 1
dpkg: dependency problems prevent configuration of software-properties-common:
 software-properties-common depends on ca-certificates; however:
  Package ca-certificates is not configured yet.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: ca-certificates 20180409
ProcVersionSignature: Ubuntu 4.13.0-39.44~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-39-generic x86_64
NonfreeKernelModules: bbswitch nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Fri Apr 27 23:23:20 2018
ErrorMessage: installed ca-certificates package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2017-04-10 (381 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
PackageArchitecture: all
Python3Details: /usr/bin/python3.6, Python 3.6.5, python3-minimal, 3.6.5-3
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.1
SourcePackage: ca-certificates
Title: package ca-certificates 20180409 failed to install/upgrade: installed ca-certificates package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Brian Murray (brian-murray)]

You have libssl1.1 from a PPA and it does not include an important bug fix which does exist in the package from the official Ubuntu archive. This causes the ca-certificates package installation to fail.

[Michel Weimerskirch (michel-weimerskirch)]

I had the same issue. Thanks for the hint with libssl1.1 being the cause. I disabled all PPAs and then reinstalled libssl1.1 as well as openssl manually by reinstalling the versions provided with Ubuntu Bionic. After that, apt-get was able to finish configuring all packages.