Could not delete variable: No space left on device (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)

[Imtiaz Ahmed]

Happened during installation. I'm a newbie Ubuntu user, so don't know any details about it.

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
.proc.sys.kernel.moksbstate_disabled: Error: [Errno 2] No such file or directory: '/proc/sys/kernel/moksbstate_disabled'
ApportVersion: 2.20.9-0ubuntu7
Architecture: amd64
Date: Thu May 3 22:59:10 2018
EFITables:
 May 03 23:03:38 imtiaz kernel: efi: EFI v2.40 by American Megatrends
 May 03 23:03:38 imtiaz kernel: efi: ESRT=0xacf77118 ACPI=0xac353000 ACPI 2.0=0xac353000 SMBIOS=0xf05b0 MPS=0xfd620
 May 03 23:03:38 imtiaz kernel: secureboot: Secure boot could not be determined (mode 0)
 May 03 23:03:38 imtiaz kernel: esrt: Reserving ESRT space from 0x00000000acf77118 to 0x00000000acf77150.
ErrorMessage: installed shim-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2018-04-20 (13 days ago)
InstallationMedia: Ubuntu 17.10 "Artful Aardvark" - Release amd64 (20180105.1)
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 2018-05-04 (0 days ago)