package grub-efi-amd64-signed 1.66.8+2.02~beta2-36ubuntu3.8 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

On startup a system error was thrown, no idea what caused it.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: grub-efi-amd64-signed 1.66.8+2.02~beta2-36ubuntu3.8
ProcVersionSignature: Ubuntu 4.8.0-41.44~16.04.1-generic 4.8.17
Uname: Linux 4.8.0-41-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.5
Architecture: amd64
Date: Sun Mar 12 18:31:57 2017
DuplicateSignature:
 package:grub-efi-amd64-signed:1.66.8+2.02~beta2-36ubuntu3.8
 Installing for x86_64-efi platform.
 grub-install: error: cannot open `/boot/efi/EFI/ubuntu/shimx64.efi': No such file or directory.
 dpkg: error processing package grub-efi-amd64-signed (--configure):
  subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationDate: Installed on 2017-02-19 (21 days ago)
InstallationMedia: Ubuntu 16.04.2 LTS "Xenial Xerus" - Release amd64 (20170215.2)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.19
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.66.8+2.02~beta2-36ubuntu3.8 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)