shutdown system dialog installation hangs

[Humphrey van Polanen Petel]

Ubuntu Software Center offers Shutdown System Dialog.
This means that it is deemed compatible with Ubuntu.
The description refers to the Mate desktop -- is that a worry?
Version to be installed is mate-gnome-main-menu-applet 1.8.0-5build1

Problem is that the install hangs halfway through (see attached).

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: software-center 16.01+16.04.20160420
ProcVersionSignature: Ubuntu 4.4.0-93.116-generic 4.4.79
Uname: Linux 4.4.0-93-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Sep 6 09:52:11 2017
ExecutablePath: /usr/share/software-center/software-center
InstallationDate: Installed on 2017-07-27 (40 days ago)
InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
InterpreterPath: /usr/bin/python2.7
PackageArchitecture: all
SourcePackage: software-center
UpgradeStatus: No upgrade log present (probably fresh install)