package shim-signed 1.33.1~16.04.5+15+1533136590.3beb971-0ubuntu1 failed to install/upgrade: subprocesso script post-installation instalado retornou erro do status de saída 1

[johnnyrave]

apt-get upgrade
after install xfce-session

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: shim-signed 1.33.1~16.04.5+15+1533136590.3beb971-0ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-145.171-generic 4.4.176
Uname: Linux 4.4.0-145-generic x86_64
.proc.sys.kernel.moksbstate_disabled: 0
ApportVersion: 2.20.1-0ubuntu2.18
Architecture: amd64
BootEFIContents:
 fw
 fwupx64.efi
Date: Mon Apr 15 22:58:58 2019
ErrorMessage: subprocesso script post-installation instalado retornou erro do status de saída 1
InstallationDate: Installed on 2019-04-08 (6 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.5
 apt 1.2.31
SecureBoot: 6 0 0 0 0
SourcePackage: shim-signed
Title: package shim-signed 1.33.1~16.04.5+15+1533136590.3beb971-0ubuntu1 failed to install/upgrade: subprocesso script post-installation instalado retornou erro do status de saída 1
UpgradeStatus: No upgrade log present (probably fresh install)

[Steve Langasek (vorlon)]

The error in your logs is:

A instalar shim-signed (1.33.1~16.04.5+15+1533136590.3beb971-0ubuntu1) ...
Installing for x86_64-efi platform.
grub-install: erro: /boot/efi doesn't look like an EFI partition.
.
dpkg: erro ao processar o pacote shim-signed (--configure):
 subprocesso script post-installation instalado retornou erro do status de saída 1

The 'df' output attached to your bug report does show /dev/sda7 mounted at /boot/efi. Please show the output of 'mount | grep /boot/efi' on your system.

[Launchpad Janitor (janitor)]

[Expired for shim-signed (Ubuntu) because there has been no activity for 60 days.]