package grub-pc 2.02~beta2-36ubuntu3.17 failed to install/upgrade: subprocess installed. post-installation script returned error exit status 10

[Francis ang Zhao Xiong]

terminal displayed this along with other stuff:
dpkg: error processing package grub-pc (--configure):
 subprocess installed post-installation script returned error exit status 10

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: grub-pc 2.02~beta2-36ubuntu3.17
ProcVersionSignature: Ubuntu 4.13.0-38.43~16.04.1-generic 4.13.16
Uname: Linux 4.13.0-38-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Thu Jun 14 18:14:48 2018
DpkgHistoryLog:
 Start-Date: 2018-06-14 18:14:43
 Commandline: apt-get install python3-tk
 Requested-By: francis (1000)
 Install: blt:amd64 (2.5.3+dfsg-3, automatic), tk8.6-blt2.5:amd64 (2.5.3+dfsg-3, automatic), python3-tk:amd64 (3.5.1-1)
DuplicateSignature:
 package:grub-pc:2.02~beta2-36ubuntu3.17
 Setting up grub-pc (2.02~beta2-36ubuntu3.17) ...
 dpkg: error processing package grub-pc (--configure):
  subprocess installed post-installation script returned error exit status 10
ErrorMessage: subprocess installed post-installation script returned error exit status 10
InstallationDate: Installed on 2017-09-26 (260 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
ProcCmdLine: BOOT_IMAGE=/vmlinuz-4.13.0-38-generic root=/dev/mapper/ubuntu--vg-root ro quiet splash vt.handoff=7
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.4
 apt 1.2.26
SourcePackage: grub2
Title: package grub-pc 2.02~beta2-36ubuntu3.17 failed to install/upgrade: subprocess installed post-installation script returned error exit status 10
UpgradeStatus: No upgrade log present (probably fresh install)

[Phillip Susi (psusi)]

Please edit /var/lib/dpkg/info/grub-pc.postinst and change the second line from set -e to set -ex, then run sudo apt-get install -f to try again and paste the output.

[Launchpad Janitor (janitor)]

[Expired for grub2 (Ubuntu) because there has been no activity for 60 days.]