[time-admin] Unlock-button is not working

[Martin Constantino–Bodin]

I just moved and I wanted to update the current time displayed in the system. I thus typed “time-admin”. A window opens, but most of its buttons are locked, except [Help], [Unlock], and [Close]. I thus clicked on [Unlock], but nothing happens. I guess that a window asking for my password was supposed to pop up.

As a consequence, I can’t change my system clock. This is frustrating, as my system clock is 5 hour late and I need to adapt to my new time here.

Here is what I got from the terminal:
$ time-admin
Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.

** (time-admin:11965): WARNING **: Error acquiring permission: Failed to acquire permission for action-id org.freedesktop.systemtoolsbackends.set

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: gnome-system-tools 3.0.0-6ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-38.43-generic 4.13.16
Uname: Linux 4.13.0-38-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.8
Architecture: amd64
CurrentDesktop: LXDE
Date: Mon Apr 16 07:35:51 2018
InstallationDate: Installed on 2016-12-05 (496 days ago)
InstallationMedia: Lubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.1)
SourcePackage: gnome-system-tools
UpgradeStatus: Upgraded to artful on 2018-01-17 (88 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.