package sgml-base 1.29 failed to install/upgrade: installed sgml-base package post-installation script subprocess returned error exit status 1

[Pete Hall]

Error message displayed after running routine upgrade process

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: sgml-base 1.29
ProcVersionSignature: Ubuntu 4.15.0-36.39-generic 4.15.18
Uname: Linux 4.15.0-36-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.4
AptOrdering:
 initramfs-tools:amd64: Install
 initramfs-tools-core:amd64: Install
 initramfs-tools-bin:amd64: Install
 metacity-common:amd64: Install
 NULL: ConfigurePending
Architecture: amd64
Date: Sun Oct 7 01:13:45 2018
DuplicateSignature:
 package:sgml-base:1.29
 Processing triggers for sgml-base (1.29) ...
 cannot rename /var/lib/sgml-base/supercatalog to /var/lib/sgml-base/supercatalog.old: Operation not permitted at /usr/sbin/update-catalog line 322.
 dpkg: error processing package sgml-base (--configure):
  installed sgml-base package post-installation script subprocess returned error exit status 1
ErrorMessage: installed sgml-base package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2018-04-27 (163 days ago)
InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426)
PackageArchitecture: all
Python3Details: /usr/bin/python3.6, Python 3.6.6, python3-minimal, 3.6.5-3ubuntu1
PythonDetails: /usr/bin/python2.7, Python 2.7.15rc1, python-minimal, 2.7.15~rc1-1
RelatedPackageVersions:
 dpkg 1.19.0.5ubuntu2
 apt 1.6.3ubuntu0.1
SourcePackage: sgml-base
Title: package sgml-base 1.29 failed to install/upgrade: installed sgml-base package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)