package grub-efi-amd64-signed 1.142.8+2.04-1ubuntu26.6 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 32

[Matthew McCutcheon]

Received software update prompt. Followed prompts as always. Received message asking for GRUB location. Selected the SSD with dual boot to WIN7 and Ubuntu 20.04.01. 64 bit.
GNOME version 3.36.3

Install failed.

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-efi-amd64-signed 1.142.8+2.04-1ubuntu26.6
ProcVersionSignature: Ubuntu 5.4.0-52.57-generic 5.4.65
Uname: Linux 5.4.0-52-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.10
Architecture: amd64
CasperMD5CheckResult: skip
Date: Tue Oct 27 13:02:58 2020
DuplicateSignature:
 package:grub-efi-amd64-signed:1.142.8+2.04-1ubuntu26.6
 Setting up grub-efi-amd64-signed (1.142.8+2.04-1ubuntu26.6) ...
 mount: /var/lib/grub/esp: special device /, does not exist.
 dpkg: error processing package grub-efi-amd64-signed (--configure):
  installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 32
ErrorMessage: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 32
InstallationDate: Installed on 2020-01-18 (283 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
Python3Details: /usr/bin/python3.8, Python 3.8.5, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: /usr/bin/python2.7, Python 2.7.18, python-is-python2, 2.7.17-4
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3
 apt 2.0.2ubuntu0.1
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.142.8+2.04-1ubuntu26.6 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 32
UpgradeStatus: Upgraded to focal on 2020-10-10 (16 days ago)

[Launchpad Janitor (janitor)]

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