warning during distribution update package grub-efi-amd64-signed 1.66.2+2.02~beta2-36ubuntu3.2 failed to install/upgrade: le sous-processus script post-installation installé a retourné une erreur de sortie d'état 1

[LEBRUN]

lebrun@LFRS1000979:~/openturns-adm/build$ lsb_release -rd
Description: Ubuntu 16.04.1 LTS
Release: 16.04

lebrun@LFRS1000979:~/openturns-adm/build$ apt-cache policy pkgname
N: « 50unattended-upgrades.ucf-dist » dans le répertoire « /etc/apt/apt.conf.d/ » a été ignoré car il utilise une extension non valable
N: Impossible de trouver le paquet pkgname

I expected a smooth upgrade with no error, and got this error and the offer to send a bug report. I hope it will help you improving this great distribution!

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: grub-efi-amd64-signed 1.66.2+2.02~beta2-36ubuntu3.2
ProcVersionSignature: Ubuntu 3.19.0-73.81~14.04.1-generic 3.19.8-ckt22
Uname: Linux 3.19.0-73-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_drm nvidia_modeset nvidia
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
Date: Sun Nov 13 10:37:23 2016
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-trusty-amd64-osp1-20150720-0
ErrorMessage: le sous-processus script post-installation installé a retourné une erreur de sortie d'état 1
InstallationDate: Installed on 2016-10-09 (35 days ago)
InstallationMedia: Ubuntu 14.04 "Trusty" - Build amd64 LIVE Binary 20150720-04:06
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.66.2+2.02~beta2-36ubuntu3.2 failed to install/upgrade: le sous-processus script post-installation installé a retourné une erreur de sortie d'état 1
UpgradeStatus: Upgraded to xenial on 2016-11-13 (0 days ago)