Failed install as part of upgrade to 18.04

[Jonathan]

As part of the upgrade from 17.04 to 18.04 this particular package virtualbox-ext-pack 5.2.10-3 failed to install/upgrade: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 4. Since the error message was shown at the very end of the installation (which otherwise lasted just under an hour).

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: virtualbox-ext-pack 5.2.10-3
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Sun Apr 29 00:40:36 2018
ErrorMessage: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 4
InstallationDate: Installed on 2018-01-28 (91 days ago)
InstallationMedia: Ubuntu-MATE 17.10 "Artful Aardvark" - Release amd64 (20180106)
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: virtualbox-ext-pack
Title: package virtualbox-ext-pack 5.2.10-3 failed to install/upgrade: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 4
UpgradeStatus: Upgraded to bionic on 2018-04-29 (0 days ago)