package virtualbox-ext-pack failed to install/upgrade: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 1

[Martin Pokorny]

Occurred on upgrade to 18.04. Disturbing, as the upgrade process just quits after that, warning about the possibility of an unstable system.

ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: virtualbox-ext-pack (not installed)
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Sat May 5 10:33:20 2018
ErrorMessage: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2015-11-15 (902 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
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 (not installed) failed to install/upgrade: installed virtualbox-ext-pack package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to bionic on 2018-05-05 (0 days ago)

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #1768042, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.