(non-UEFI) this always happened when installing new apps: package shim-signed 1.27~16.04.1+0.9+1474479173.6c180c6-1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

this always happened when installing new apps
i just ignored it, sometimes the apps work, hit and miss

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: shim-signed 1.27~16.04.1+0.9+1474479173.6c180c6-1ubuntu1
ProcVersionSignature: Ubuntu 4.8.0-52.55~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-52-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
BootEFIContents:
 fw
 fwupx64.efi
Date: Mon Aug 28 12:52:25 2017
DpkgHistoryLog:
 Start-Date: 2017-08-28 12:51:46
 Commandline: aptdaemon role='role-commit-packages' sender=':1.42'
 Install: libgegl-0.3-0:amd64 (0.3.4-1ubuntu2, automatic), gimp-help-common:amd64 (2.8.2-0.1, automatic), libraw15:amd64 (0.17.1-1, automatic), gimp-data:amd64 (2.8.16-1ubuntu1.1, automatic), gimp:amd64 (2.8.16-1ubuntu1.1, automatic), libgutenprintui2-1:amd64 (5.2.11-1, automatic), libilmbase12:amd64 (2.2.0-11ubuntu2, automatic), libbabl-0.1-0:amd64 (0.1.16-1, automatic), gimp-gmic:amd64 (1.6.8-3), libgutenprint2:amd64 (5.2.11-1, automatic), gutenprint-locales:amd64 (5.2.11-1, automatic), libopenexr22:amd64 (2.2.0-10ubuntu2, automatic), gimp-gutenprint:amd64 (5.2.11-1), python-gtk2:amd64 (2.24.0-4ubuntu1, automatic), libgimp2.0:amd64 (2.8.16-1ubuntu1.1, automatic), libjasper1:amd64 (1.900.1-debian1-2.4ubuntu1.1, automatic), gimp-help-en:amd64 (2.8.2-0.1, automatic), python-gobject-2:amd64 (2.28.6-12ubuntu1, automatic)
DuplicateSignature:
 package:shim-signed:1.27~16.04.1+0.9+1474479173.6c180c6-1ubuntu1
 Setting up grub-efi-amd64-signed (1.66.9+2.02~beta2-36ubuntu3.9) ...
 grub-install: error: /usr/lib/grub/i386-pc/modinfo.sh doesn't exist. Please specify --target or --directory.
 dpkg: error processing package grub-efi-amd64-signed (--configure):
  subprocess installed post-installation script returned error exit status 1
EFIBootMgr: Error: command ['efibootmgr', '-v'] failed with exit code 2: efibootmgr: EFI variables are not supported on this system.
ErrorMessage: subprocess installed post-installation script returned error exit status 1
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.20
SourcePackage: shim-signed
Title: package shim-signed 1.27~16.04.1+0.9+1474479173.6c180c6-1ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)