package grub-efi-amd64-signed 1.155.2+2.04-1ubuntu35.2 failed to install/upgrade: »installiertes grub-efi-amd64-signed-Skript des Paketes post-installation«-Unterprozess gab den Fehlerwert 1 zurück

[Kaan]

Just installed Ubuntu 20.10 on my older laptop (which was running Windows 10 Pro).
Installed by USB drive, 3rd installation and still get the same issue.

ProblemType: Package
DistroRelease: Ubuntu 20.10
Package: grub-efi-amd64-signed 1.155.2+2.04-1ubuntu35.2
ProcVersionSignature: Ubuntu 5.8.0-41.46-generic 5.8.18
Uname: Linux 5.8.0-41-generic x86_64
ApportVersion: 2.20.11-0ubuntu50
Architecture: amd64
CasperMD5CheckResult: skip
Date: Sun Jan 31 08:24:14 2021
ErrorMessage: »installiertes grub-efi-amd64-signed-Skript des Paketes post-installation«-Unterprozess gab den Fehlerwert 1 zurück
InstallationDate: Installed on 2021-01-31 (0 days ago)
InstallationMedia: Ubuntu 20.10 "Groovy Gorilla" - Release amd64 (20201022)
Python3Details: /usr/bin/python3.8, Python 3.8.6, python3-minimal, 3.8.6-0ubuntu1
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.20.5ubuntu2
 apt 2.1.10
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.155.2+2.04-1ubuntu35.2 failed to install/upgrade: »installiertes grub-efi-amd64-signed-Skript des Paketes post-installation«-Unterprozess gab den Fehlerwert 1 zurück
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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