package grub-efi-amd64 2.02~beta2-36ubuntu3.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 128

I was upgrading.

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: grub-efi-amd64 2.02~beta2-36ubuntu3.6
ProcVersionSignature: Ubuntu 4.4.0-57.78-generic 4.4.35
Uname: Linux 4.4.0-57-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.4
Architecture: amd64
Date: Thu Dec 29 19:06:47 2016
DeviceMap:
 (hd0) /dev/sda
 (hd1) /dev/sdb
 (hd2) /dev/sdc
DuplicateSignature:
 package:grub-efi-amd64:2.02~beta2-36ubuntu3.6
 Setting up grub-efi-amd64 (2.02~beta2-36ubuntu3.6) ...
 dpkg: error processing package grub-efi-amd64 (--configure):
  subprocess installed post-installation script returned error exit status 128
ErrorMessage: subprocess installed post-installation script returned error exit status 128
InstallationDate: Installed on 2015-07-23 (525 days ago)
InstallationMedia: Ubuntu-MATE 15.04 "Vivid Vervet" - Release amd64 (20150422.1)
InvalidGrubScript: /etc/grub.d/25_custom
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-57-generic root=UUID=1d1d6fb0-7eb6-4b64-a5ee-cadfca22c2c6 ro quiet splash
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.18
SourcePackage: grub2
Title: package grub-efi-amd64 2.02~beta2-36ubuntu3.6 failed to install/upgrade: subprocess installed post-installation script returned error exit status 128
UpgradeStatus: No upgrade log present (probably fresh install)