Could not delete variable: Invalid argument (package shim-signed 1.34.9+13-0ubuntu2 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 1)

[Oliver Anteros]

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ProblemType: Package
DistroRelease: Ubuntu 18.04
Package: shim-signed 1.34.9+13-0ubuntu2
ProcVersionSignature: Ubuntu 4.15.0-20.21-generic 4.15.17
Uname: Linux 4.15.0-20-generic x86_64
NonfreeKernelModules: wl
.proc.sys.kernel.moksbstate_disabled: Error: [Errno 2] No such file or directory: '/proc/sys/kernel/moksbstate_disabled'
ApportVersion: 2.20.9-0ubuntu7
AptOrdering: NULL: ConfigurePending
Architecture: amd64
Date: Thu May 3 14:52:46 2018
DpkgHistoryLog:
 Start-Date: 2018-05-03 14:52:45
 Requested-By: olian04 (1000)
ErrorMessage: installed shim-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2017-09-05 (239 days ago)
InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
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
SecureBoot: 6 0 0 0 0
SourcePackage: shim-signed
Title: package shim-signed 1.34.9+13-0ubuntu2 failed to install/upgrade: installed shim-signed package post-installation script subprocess returned error exit status 1
UpgradeStatus: Upgraded to bionic on 2018-05-03 (0 days ago)

[Launchpad Janitor (janitor)]

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