package friendly-recovery 0.2.31ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

failed

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: friendly-recovery 0.2.31ubuntu2.1
ProcVersionSignature: Ubuntu 3.13.0-170.220-generic 3.13.11-ckt39
Uname: Linux 3.13.0-170-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.23
Architecture: amd64
Date: Thu Apr 2 19:50:29 2020
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-trusty-amd64-20140620-0
DuplicateSignature:
 package:friendly-recovery:0.2.31ubuntu2.1
 Installing new version of config file /etc/kernel/postrm.d/zz-update-grub ...
 /var/lib/dpkg/info/grub-efi-amd64.config: 35: /etc/default/grub: Syntax error: EOF in backquote substitution
 dpkg: error processing package grub-efi-amd64 (--configure):
  subprocess installed post-installation script returned error exit status 2
ErrorMessage: subprocess installed post-installation script returned error exit status 2
InstallationDate: Installed on 2017-12-05 (849 days ago)
InstallationMedia: Ubuntu 14.04 "Trusty" - Build amd64 LIVE Binary 20140620-04:25
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.6
 apt 1.2.32
SourcePackage: friendly-recovery
Title: package friendly-recovery 0.2.31ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: Upgraded to xenial on 2020-04-02 (0 days ago)
upstart.friendly-recovery.override: manual