lock screen not working, neither Win+L nor suspend works to lock the screen

[Catalin]

neither Win+L nor suspend works to lock screen
gnome-screensaver-command -l returns Timeout was reached, Did not receive a reply from the screensaver.

Description: Ubuntu 20.04 LTS
Release: 20.04
Codename: focal

gnome-screensaver:
  Installed: 3.6.1-11ubuntu4
  Candidate: 3.6.1-11ubuntu4

Win+L should lock the screen or otherwise other shortcut/option, including suspend shall do that.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: gnome-screensaver 3.6.1-11ubuntu4
ProcVersionSignature: Ubuntu 5.4.0-42.46-generic 5.4.44
Uname: Linux 5.4.0-42-generic x86_64
ApportVersion: 2.20.11-0ubuntu27.4
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: ubuntu:GNOME
Date: Tue Jul 28 18:39:50 2020
GnomeSessionIdleInhibited: No
GnomeSessionInhibitors: None
GsettingsGnomeSession:
 org.gnome.desktop.session session-name 'ubuntu'
 org.gnome.desktop.session idle-delay uint32 300
InstallationDate: Installed on 2020-02-13 (166 days ago)
InstallationMedia: Ubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017)
SourcePackage: gnome-screensaver
UpgradeStatus: Upgraded to focal on 2020-05-13 (76 days ago)

[Sebastien Bacher (seb128)]

Thank you for your bug report, could you give some details on your login manager and desktop? gnome-screensaver is a legacy component and not supposed to be installed or used in a GNOME session
Could you also add your 'journalctl -b 0' log after triggering the issue?

[Catalin (b247)]

Hi, thank you for the response,
Hope this will help:

cat /etc/X11/default-display-manager
/usr/sbin/gdm3

Gnome 3.36.3 X11

journalctl -b 0

iul 29 18:07:12 ubuntu pkexec[6569]: catalin: Executing command
[USER=root] [TTY=unknown] [CWD=/home/catalin]
[COMMAND=/usr/lib/update-notifier/package-system-locked]
iul 29 18:07:18 ubuntu dbus-daemon[3695]: apparmor="DENIED"
operation="dbus_method_call"  bus="session"
path="/org/gtk/Notifications" interface="org.gtk.Notifications">
iul 29 18:07:26 ubuntu gnome-shell[4305]: Screen lock is locked down,
not locking
iul 29 18:07:39 ubuntu gnome-shell[4305]: Screen lock is locked down,
not locking

iul 29 18:07:51 ubuntu gsd-media-keys[4697]: Couldn't lock screen:
Timeout was reached
iul 29 18:07:59 ubuntu gnome-shell[4305]: Screen lock is locked down,
not locking
iul 29 18:08:04 ubuntu gsd-media-keys[4697]: Couldn't lock screen:
Timeout was reached
iul 29 18:08:05 ubuntu gsd-media-keys[4697]: Couldn't lock screen:
Timeout was reached

------------------------------------------------------------------------
*From:* Sebastien Bacher [mailto:<email address hidden>]
*Sent:* Wednesday, July 29, 2020, 12:22 UTC+3
*To:* <email address hidden>
*Subject:* [Bug 1889277] Re: lock screen not working, neither Win+L nor
suspend works to lock the screen

> Thank you for your bug report, could you give some details on your login manager and desktop? gnome-screensaver is a legacy component and not supposed to be installed or used in a GNOME session
> Could you also add your 'journalctl -b 0' log after triggering the issue?
>
> ** Changed in: gnome-screensaver (Ubuntu)
> Importance: Undecided => Low
>
> ** Changed in: gnome-screensaver (Ubuntu)
> Status: New => Incomplete
>

[Catalin (b247)]

Dear Sebastian,
I've managed to solve the problem by following a 2017 instructions from
Arch Linux (https://bbs.archlinux.org/viewtopic.php?id=227258).

journalctl -b 0 helped me

Thank You,
------------------------------------------------------------------------
*From:* Sebastien Bacher [mailto:<email address hidden>]
*Sent:* Wednesday, July 29, 2020, 12:22 UTC+3
*To:* <email address hidden>
*Subject:* [Bug 1889277] Re: lock screen not working, neither Win+L nor
suspend works to lock the screen

> Thank you for your bug report, could you give some details on your login manager and desktop? gnome-screensaver is a legacy component and not supposed to be installed or used in a GNOME session
> Could you also add your 'journalctl -b 0' log after triggering the issue?
>
> ** Changed in: gnome-screensaver (Ubuntu)
> Importance: Undecided => Low
>
> ** Changed in: gnome-screensaver (Ubuntu)
> Status: New => Incomplete
>

[Sebastien Bacher (seb128)]

so was the issue than the config disable-lock-screen was enabled?

[Catalin (b247)]

Sorry for that, yes, it was, but don't know why, the issue appears
suddenly (maybe after an update, dist or packages, or by pressing some
strange key combination). Is there a way to check/see when or what has
triggered this conf rule change?

I had to install the dconf-editor to change it back (disable-lock-screen
from true to false).

------------------------------------------------------------------------
*From:* Sebastien Bacher [mailto:<email address hidden>]
*Sent:* Thursday, July 30, 2020, 12:08 UTC+3
*To:* <email address hidden>
*Subject:* [Bug 1889277] Re: lock screen not working, neither Win+L nor
suspend works to lock the screen

> so was the issue than the config disable-lock-screen was enabled?
>

[Sebastien Bacher (seb128)]

Sorry but there is no recording on how and when the key was change, could be that you used some configuration interface that includes a such option. Anyway closing since it's not really a bug in the software

[Launchpad Janitor (janitor)]

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

[Jaromir Obr (jaromir-obr)]

I hit the same issue in Ubuntu 24.04. I noticed that after a resume from the suspend mode, I wasn't prompted to enter a password and was logged in automatically (which isn't too safe). Nor "Super + L" worked.

The setting "disable-lock-screen" was "true" from some reason.
"gsettings set org.gnome.desktop.lockdown disable-lock-screen false" solved the issue.

But I have no idea why the setting was "true". I installed a fresh OS a few days ago and I'm not aware that I changed the option from "false" to "true". Maybe it was changed by an upgrade or installation of some tool .....?

Nevertheless it's working now.