Just adding that I’ve had the same issue and am unable to input my password after activating the lock screen, as it just flickers back and forth between the screensaver and the window manager, wiping out the password entry each time.
xset -dpms and xset s off
The above method is a method documented in archlinux wiki.
It only disables DPMS after booting, the DPMS’s full function will recover at a new reboot.
It is also the final method in xfce to block DPMS unless the DPMS is uninstalled.
In my own experience, i always made any time counter in xfce4-screensaver-preferences to 9999.
In almost all xfce desktops of arch based distros, above setting not yet met any trouble.
As to the other desktops, my knowledge is very limited as compared to you.
In case someone may use xfce, he can make changes in /etc/lightdm/lightdm.conf to the followings:
[Seat:*]
#greeter-session=lightdm-gtk-greeter
user-session=xfce
autologin-user=user-name
autologin-user-timeout=0
autologin-session=xfce
$ sudo groupadd -r autologin
$ sudo gpasswd -a user-name autologin
unfortunately downgrade of all three packages have not helped me either.
Installation of libxfce4ui-devil, could be a solution, but do not want to implement right now. Only workaround is me just open other TTY and kill lightdm.
Someone needs to take a serious look at this issue.
Do you mean to visit the users’ homes/offices?
Remotely, we can only inspect logs that you will post.
Post journal and Xorg logs, for a chance of assisting. 
1 Like
with pleasure. attached: .xsesson, dmlight und xorg log.
And i find following in syslog
[ 59.884338] traps: xfce4-screensav[2845] general protection fault ip:55b748441f71 sp:7ffdb0956250 error:0 in xfce4-screensaver-dialog[55b74843a000+b000]
[ 86.307162] traps: xfce4-screensav[3446] general protection fault ip:564137b83f71 sp:7ffff68607d0 error:0 in xfce4-screensaver-dialog[564137b7c000+b000]
[ 89.897384] traps: xfce4-screensav[3486] general protection fault ip:564d4c274f71 sp:7ffefce6b760 error:0 in xfce4-screensaver-dialog[564d4c26d000+b000]
[ 92.667524] traps: xfce4-screensav[3526] general protection fault ip:55c6bf18af71 sp:7ffd5f854ce0 error:0 in xfce4-screensaver-dialog[55c6bf183000+b000]
[ 94.827546] traps: xfce4-screensav[3566] general protection fault ip:5570399d3f71 sp:7ffc48484130 error:0 in xfce4-screensaver-dialog[5570399cc000+b000]
[ 96.432692] traps: xfce4-screensav[3606] general protection fault ip:562f41c47f71 sp:7ffcee2dd300 error:0 in xfce4-screensaver-dialog[562f41c40000+b000]
[ 98.067588] traps: xfce4-screensav[3646] general protection fault ip:55ce1af8bf71 sp:7ffea893e660 error:0 in xfce4-screensaver-dialog[55ce1af84000+b000]
[ 100.943827] traps: xfce4-screensav[3686] general protection fault ip:56435657cf71 sp:7ffc86ff5f10 error:0 in xfce4-screensaver-dialog[564356575000+b000]
[ 104.632290] traps: xfce4-screensav[3726] general protection fault ip:55d56637af71 sp:7ffc9eb2b640 error:0 in xfce4-screensaver-dialog[55d566373000+b000]
[ 108.842503] traps: xfce4-screensav[3767] general protection fault ip:55e0c8ceaf71 sp:7ffe68ee9760 error:0 in xfce4-screensaver-dialog[55e0c8ce3000+b000]
[ 218.839168] traps: xfce4-screensav[3966] general protection fault ip:55c93a70df71 sp:7ffd0b2dc2e0 error:0 in xfce4-screensaver-dialog[55c93a706000+b000]
lightdm.log
[+0.00s] DEBUG: Logging to /var/log/lightdm/lightdm.log
[+0.00s] DEBUG: Starting Light Display Manager 1.32.0, UID=0 PID=32789
[+0.00s] DEBUG: Loading configuration dirs from /usr/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /usr/local/share/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration dirs from /etc/xdg/lightdm/lightdm.conf.d
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf.d/10-eos-slick.conf
[+0.00s] DEBUG: Loading configuration from /etc/lightdm/lightdm.conf
[+0.00s] DEBUG: Registered seat module local
[+0.00s] DEBUG: Registered seat module xremote
[+0.00s] DEBUG: Using D-Bus name org.freedesktop.DisplayManager
[+0.00s] DEBUG: Using cross-namespace EXTERNAL authentication (this will deadlock if server is GDBus < 2.73.3)
[+0.00s] DEBUG: _g_io_module_get_default: Found default implementation local (GLocalVfs) for ‘gio-vfs’
[+0.01s] DEBUG: Monitoring logind for seats
[+0.01s] DEBUG: New seat added from logind: seat0
[+0.01s] DEBUG: Seat seat0: Loading properties from config section Seat:*
[+0.01s] DEBUG: Seat seat0 has property CanMultiSession=no
[+0.01s] DEBUG: Seat seat0: Starting
[+0.01s] DEBUG: Seat seat0: Creating greeter session
[+0.01s] DEBUG: Seat seat0: Creating display server of type x
[+0.01s] DEBUG: Could not run plymouth --ping: Failed to execute child process “plymouth” (No such file or directory)
[+0.01s] DEBUG: Using VT 7
[+0.01s] DEBUG: Seat seat0: Starting local X display on VT 7
[+0.01s] DEBUG: XServer 0: Logging to /var/log/lightdm/x-0.log
[+0.01s] DEBUG: XServer 0: Writing X server authority to /run/lightdm/root/:0
[+0.01s] DEBUG: XServer 0: Launching X Server
[+0.01s] DEBUG: Launching process 32797: /usr/bin/X :0 -seat seat0 -auth /run/lightdm/root/:0 -nolisten tcp vt7 -novtswitch
[+0.01s] DEBUG: XServer 0: Waiting for ready signal from X server :0
[+0.01s] DEBUG: Acquired bus name org.freedesktop.DisplayManager
[+0.01s] DEBUG: Registering seat with bus path /org/freedesktop/DisplayManager/Seat0
[+0.31s] DEBUG: Loading users from org.freedesktop.Accounts
[+0.31s] DEBUG: User /org/freedesktop/Accounts/User1000 added
[+0.32s] DEBUG: Seat seat0 changes active session to 13
[+1.57s] DEBUG: Got signal 10 from process 32797
[+1.57s] DEBUG: XServer 0: Got signal from X server :0
[+1.57s] DEBUG: XServer 0: Connecting to XServer :0
[+1.57s] DEBUG: Seat seat0: Display server ready, starting session authentication
[+1.57s] DEBUG: Session pid=32807: Started with service 'lightdm-greeter', username 'lightdm'
[+1.59s] DEBUG: Session pid=32807: Authentication complete with return value 0: Success
[+1.59s] DEBUG: Seat seat0: Session authenticated, running command
[+1.59s] DEBUG: Session pid=32807: Running command /usr/bin/slick-greeter
[+1.59s] DEBUG: Creating shared data directory /var/lib/lightdm-data/lightdm
[+1.59s] DEBUG: Session pid=32807: Logging to /var/log/lightdm/seat0-greeter.log
[+1.79s] DEBUG: Activating VT 7
[+1.79s] DEBUG: Activating login1 session c6
[+1.79s] DEBUG: Seat seat0 changes active session to c6
[+1.79s] DEBUG: Session c6 is already active
[+2.05s] DEBUG: Greeter connected version=1.32.0 api=1 resettable=false
[+2.34s] DEBUG: Greeter start authentication for user-01
[+2.34s] DEBUG: Session pid=32879: Started with service 'lightdm', username 'user-01'
[+2.35s] DEBUG: Session pid=32879: Got 1 message(s) from PAM
[+2.35s] DEBUG: Prompt greeter with 1 message(s)
[+6.45s] DEBUG: Continue authentication
[+6.47s] DEBUG: Session pid=32879: Authentication complete with return value 0: Success
[+6.47s] DEBUG: Authenticate result for user user-01: Success
[+6.47s] DEBUG: User user-01 authorized
[+6.47s] DEBUG: Greeter requests session xfce
[+6.47s] DEBUG: Seat seat0: Stopping greeter; display server will be re-used for user session
[+6.47s] DEBUG: Terminating login1 session c6
[+6.47s] DEBUG: Session pid=32807: Sending SIGTERM
[+6.49s] DEBUG: Greeter closed communication channel
[+6.49s] DEBUG: Session pid=32807: Exited with return value 0
[+6.49s] DEBUG: Seat seat0: Session stopped
[+6.49s] DEBUG: Seat seat0: Greeter stopped, running session
[+6.49s] DEBUG: Registering session with bus path /org/freedesktop/DisplayManager/Session0
[+6.49s] DEBUG: Session pid=32879: Running command /etc/lightdm/Xsession startxfce4
[+6.49s] DEBUG: Creating shared data directory /var/lib/lightdm-data/user-01
[+6.49s] DEBUG: Session pid=32879: Logging to .xsession-errors
[+6.56s] DEBUG: Activating VT 7
[+6.56s] DEBUG: Activating login1 session 15
[+6.56s] DEBUG: Seat seat0 changes active session to
[+6.56s] DEBUG: Seat seat0 changes active session to 15
[+6.56s] DEBUG: Session 15 is already active
.xsession_errors
gpg-agent: Ein gpg-agent läuft bereits - ein weiterer wird nicht gestartet
(xfce4-session:32903): xfce4-session-WARNING **: 13:39:58.619: Unable to launch "/opt/mattermost-desktop-4.6.2-linux-x64/mattermost-desktop" (specified by autostart/mattermost-desktop.desktop): Kindprozess »/opt/mattermost-desktop-4.6.2-linux-x64/mattermost-desktop« konnte nicht ausgeführt werden (Datei oder Verzeichnis nicht gefunden)
xfce4-notifyd-Message: 13:39:58.787: Your sqlite library does not support OFFSET/LIMIT with DELETE; falling back to less-efficient deletion method
** (xfce4-screensaver:33038): WARNING **: 13:39:58.926: Bildschirmschoner läuft bereits in dieser Sitzung
(xfce4-power-manager:33000): xfce4-power-manager-WARNING **: 13:39:58.929: could not map keysym 1008ffa8 to keycode
(xfce4-power-manager:33000): xfce4-power-manager-WARNING **: 13:39:58.959: It seems the kernel brightness switch handling value was not restored properly on exit last time, xfce4-power-manager will try to restore it this time.
(xfce4-power-manager:33000): xfce4-power-manager-WARNING **: 13:39:58.960: Unable to set the kernel brightness switch parameter to 0.
blueman-applet 13.39.58 WARNING PluginManager:151 __load_plugin: Not loading DhcpClient because its conflict has higher priority
blueman-applet 13.39.59 WARNING PluginManager:151 __load_plugin: Not loading PPPSupport because its conflict has higher priority
Welcome App ist deaktiviert. Um sie zu starten, benutze --enable.
(tilix:34674): GLib-GObject-CRITICAL **: 13:40:04.580: invalid (NULL) pointer instance
(tilix:34674): GLib-GObject-CRITICAL **: 13:40:04.580: g_signal_handlers_disconnect_matched: assertion 'G_TYPE_CHECK_INSTANCE (instance)' failed
xorg.0.log
[ 17216.256] (II) XINPUT: Adding extended input device "Intel HID events" (type: KEYBOARD, id 23)
[ 17216.256] (**) Option "xkb_layout" "de"
[ 17216.257] (II) event4 - Intel HID events: is tagged by udev as: Keyboard
[ 17216.257] (II) event4 - Intel HID events: device is a keyboard
[ 17216.259] (II) config/udev: Adding input device AT Translated Set 2 keyboard (/dev/input/event3)
[ 17216.259] (**) AT Translated Set 2 keyboard: Applying InputClass "devname"
[ 17216.259] (**) AT Translated Set 2 keyboard: Applying InputClass "libinput keyboard catchall"
[ 17216.259] (**) AT Translated Set 2 keyboard: Applying InputClass "system-keyboard"
[ 17216.259] (II) Using input driver 'libinput' for 'AT Translated Set 2 keyboard'
[ 17216.259] (**) AT Translated Set 2 keyboard: always reports core events
[ 17216.259] (**) Option "Device" "/dev/input/event3"
[ 17216.260] (II) event3 - AT Translated Set 2 keyboard: is tagged by udev as: Keyboard
[ 17216.260] (II) event3 - AT Translated Set 2 keyboard: device is a keyboard
[ 17216.263] (II) event3 - AT Translated Set 2 keyboard: device removed
[ 17216.289] (**) Option "config_info" "udev:/sys/devices/platform/i8042/serio0/input/input3/event3"
[ 17216.289] (II) XINPUT: Adding extended input device "AT Translated Set 2 keyboard" (type: KEYBOARD, id 24)
[ 17216.289] (**) Option "xkb_layout" "de"
[ 17216.291] (II) event3 - AT Translated Set 2 keyboard: is tagged by udev as: Keyboard
[ 17216.291] (II) event3 - AT Translated Set 2 keyboard: device is a keyboard
[ 17216.295] (II) config/udev: Adding input device TPPS/2 JYT_Synaptics TrackPoint (/dev/input/event11)
[ 17216.295] (**) TPPS/2 JYT_Synaptics TrackPoint: Applying InputClass "devname"
[ 17216.295] (**) TPPS/2 JYT_Synaptics TrackPoint: Applying InputClass "libinput pointer catchall"
[ 17216.295] (II) Using input driver 'libinput' for 'TPPS/2 JYT_Synaptics TrackPoint'
[ 17216.295] (**) TPPS/2 JYT_Synaptics TrackPoint: always reports core events
[ 17216.295] (**) Option "Device" "/dev/input/event11"
[ 17216.296] (II) event11 - TPPS/2 JYT_Synaptics TrackPoint: is tagged by udev as: Mouse Pointingstick
[ 17216.297] (II) event11 - TPPS/2 JYT_Synaptics TrackPoint: device is a pointer
[ 17216.300] (II) event11 - TPPS/2 JYT_Synaptics TrackPoint: device removed
[ 17216.342] (**) Option "config_info" "udev:/sys/devices/platform/i8042/serio1/input/input6/event11"
[ 17216.342] (II) XINPUT: Adding extended input device "TPPS/2 JYT_Synaptics TrackPoint" (type: MOUSE, id 25)
[ 17216.343] (**) Option "AccelerationScheme" "none"
[ 17216.343] (**) TPPS/2 JYT_Synaptics TrackPoint: (accel) selected scheme none/0
[ 17216.343] (**) TPPS/2 JYT_Synaptics TrackPoint: (accel) acceleration factor: 2.000
[ 17216.343] (**) TPPS/2 JYT_Synaptics TrackPoint: (accel) acceleration threshold: 4
[ 17216.344] (II) event11 - TPPS/2 JYT_Synaptics TrackPoint: is tagged by udev as: Mouse Pointingstick
[ 17216.345] (II) event11 - TPPS/2 JYT_Synaptics TrackPoint: device is a pointer
[ 17216.348] (II) config/udev: Adding input device TPPS/2 JYT_Synaptics TrackPoint (/dev/input/mouse1)
[ 17216.348] (**) TPPS/2 JYT_Synaptics TrackPoint: Applying InputClass "devname"
[ 17216.348] (II) Using input driver 'libinput' for 'TPPS/2 JYT_Synaptics TrackPoint'
[ 17216.348] (**) TPPS/2 JYT_Synaptics TrackPoint: always reports core events
[ 17216.348] (**) Option "Device" "/dev/input/mouse1"
[ 17216.386] (II) mouse1 - not using input device '/dev/input/mouse1'.
[ 17216.386] (EE) libinput: TPPS/2 JYT_Synaptics TrackPoint: Failed to create a device for /dev/input/mouse1
[ 17216.386] (EE) PreInit returned 2 for "TPPS/2 JYT_Synaptics TrackPoint"
[ 17216.386] (II) UnloadModule: "libinput"
[ 17216.386] (II) config/udev: Adding input device PC Speaker (/dev/input/event5)
[ 17216.386] (**) PC Speaker: Applying InputClass "devname"
[ 17216.386] (II) Using input driver 'libinput' for 'PC Speaker'
[ 17216.386] (**) PC Speaker: always reports core events
[ 17216.386] (**) Option "Device" "/dev/input/event5"
[ 17216.387] (II) event5 - PC Speaker: not tagged as supported input device
[ 17216.419] (II) event5 - not using input device '/dev/input/event5'.
[ 17216.419] (EE) libinput: PC Speaker: Failed to create a device for /dev/input/event5
[ 17216.419] (EE) PreInit returned 2 for "PC Speaker"
[ 17216.419] (II) UnloadModule: "libinput"
[ 17216.423] (II) config/udev: Adding input device ThinkPad Extra Buttons (/dev/input/event10)
[ 17216.423] (**) ThinkPad Extra Buttons: Applying InputClass "devname"
[ 17216.423] (**) ThinkPad Extra Buttons: Applying InputClass "libinput keyboard catchall"
[ 17216.423] (**) ThinkPad Extra Buttons: Applying InputClass "system-keyboard"
[ 17216.423] (II) Using input driver 'libinput' for 'ThinkPad Extra Buttons'
[ 17216.423] (**) ThinkPad Extra Buttons: always reports core events
[ 17216.423] (**) Option "Device" "/dev/input/event10"
[ 17216.424] (II) event10 - ThinkPad Extra Buttons: is tagged by udev as: Keyboard Switch
[ 17216.424] (II) event10 - ThinkPad Extra Buttons: device is a keyboard
[ 17216.425] (II) event10 - ThinkPad Extra Buttons: device removed
[ 17216.446] (**) Option "config_info" "udev:/sys/devices/platform/thinkpad_acpi/input/input11/event10"
[ 17216.446] (II) XINPUT: Adding extended input device "ThinkPad Extra Buttons" (type: KEYBOARD, id 26)
[ 17216.446] (**) Option "xkb_layout" "de"
[ 17216.447] (II) event10 - ThinkPad Extra Buttons: is tagged by udev as: Keyboard Switch
[ 17216.447] (II) event10 - ThinkPad Extra Buttons: device is a keyboard
[ 17216.473] (**) DP-3: Applying InputClass "devname"
[ 17216.474] (**) DP-3: Applying InputClass "libinput keyboard catchall"
[ 17216.474] (**) DP-3: Applying InputClass "system-keyboard"
[ 17216.474] (II) Using input driver 'libinput' for 'DP-3'
[ 17216.474] (**) DP-3: always reports core events
[ 17216.474] (**) Option "Device" "/dev/input/event21"
[ 17216.474] (II) libinput: DP-3: is a virtual subdevice
[ 17216.474] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:02.0/rc/rc0/input27/event21"
[ 17216.474] (II) XINPUT: Adding extended input device "DP-3" (type: KEYBOARD, id 27)
[ 17216.474] (**) Option "xkb_layout" "de"
[ 17216.474] (**) Compx 2.4G Wireless Receiver Keyboard: Applying InputClass "devname"
[ 17216.474] (**) Compx 2.4G Wireless Receiver Keyboard: Applying InputClass "libinput keyboard catchall"
[ 17216.474] (**) Compx 2.4G Wireless Receiver Keyboard: Applying InputClass "system-keyboard"
[ 17216.474] (II) Using input driver 'libinput' for 'Compx 2.4G Wireless Receiver Keyboard'
[ 17216.474] (**) Compx 2.4G Wireless Receiver Keyboard: always reports core events
[ 17216.474] (**) Option "Device" "/dev/input/event15"
[ 17216.474] (II) libinput: Compx 2.4G Wireless Receiver Keyboard: is a virtual subdevice
[ 17216.474] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:14.0/usb3/3-6/3-6.3/3-6.3.4/3-6.3.4.3/3-6.3.4.3:1.1/0003:25A7:FA70.0004/input/input20/event15"
[ 17216.474] (II) XINPUT: Adding extended input device "Compx 2.4G Wireless Receiver Keyboard" (type: KEYBOARD, id 28)
[ 17216.474] (**) Option "xkb_layout" "de"
[ 17216.474] (**) RAPOO Rapoo 2.4G Wireless Device Consumer Control: Applying InputClass "devname"
[ 17216.474] (**) RAPOO Rapoo 2.4G Wireless Device Consumer Control: Applying InputClass "libinput keyboard catchall"
[ 17216.474] (**) RAPOO Rapoo 2.4G Wireless Device Consumer Control: Applying InputClass "system-keyboard"
[ 17216.474] (II) Using input driver 'libinput' for 'RAPOO Rapoo 2.4G Wireless Device Consumer Control'
[ 17216.474] (**) RAPOO Rapoo 2.4G Wireless Device Consumer Control: always reports core events
[ 17216.474] (**) Option "Device" "/dev/input/event18"
[ 17216.474] (II) libinput: RAPOO Rapoo 2.4G Wireless Device Consumer Control: is a virtual subdevice
[ 17216.474] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:14.0/usb3/3-6/3-6.3/3-6.3.4/3-6.3.4.4/3-6.3.4.4:1.1/0003:24AE:2013.0006/input/input24/event18"
[ 17216.474] (II) XINPUT: Adding extended input device "RAPOO Rapoo 2.4G Wireless Device Consumer Control" (type: KEYBOARD, id 29)
[ 17216.474] (**) Option "xkb_layout" "de"
[ 17216.992] (II) intel(0): EDID vendor "CSO", prod id 4867
[ 17216.992] (II) intel(0): Printing DDC gathered Modelines:
[ 17216.992] (II) intel(0): Modeline "2160x1350"x0.0 180.00 2160 2176 2192 2204 1350 1358 1359 1367 -hsync -vsync (81.7 kHz eP)
[ 17216.992] (II) intel(0): Modeline "2160x1350"x0.0 90.40 2160 2176 2192 2204 1350 1358 1359 1367 -hsync -vsync (41.0 kHz e)
[ 17221.898] (II) intel(0): resizing framebuffer to 5120x1440
[ 17222.307] (II) intel(0): switch to mode 2560x1440@60.0 on DP2 using pipe 1, position (2560, 0), rotation normal, reflection none
[ 17222.690] (II) intel(0): switch to mode 2560x1440@74.8 on DP3 using pipe 2, position (0, 0), rotation normal, reflection none
a workaround could be to remove xfce4-screensaver all together and use light-locker instead:
yay -Rc xfce4-screensaver
yay -S light-locker
reboot and check…
3 Likes
best workaround which works. Thanks 
I remember xfce had issues when using more than one screensaver/DPMS method.
There can be only one!
If using only light-locker solves the issue, then a bug report upstream xfce should be done (if not already).
As for xsession-errors, since it doesn’t keep date/time stamps, messages might be old, so it needs to be cleared before troubleshooting.
It’s worth checking out the messages, though.
An invalid autostart entry trolls…
A possible brightness misconfiguration could be related to OT, depending on HW.
If this issue was pure xfce, then all xfce users would be affected.
Finally, main logs that are most helpful we should start from, are the journal logs (journalctl).
Thanks for your reply.
the logs I had produced during the problem and are up to date.
I need a bit of time if you need all entire of journalctl, but there is the following coredump exactly during the issue, after which comes that I have killed lightdm.
Mär 15 14:10:45 N-130-000 systemd[1]: systemd-coredump@49-36647-0.service: Deactivated successfully.
Mär 15 14:10:49 N-130-000 kernel: traps: xfce4-screensav[36655] general protection fault ip:5607eee70f71 sp:7fffcdab7af0 error:0 in xfce4-screensaver-dialog[5607eee69000+b000]
Mär 15 14:10:49 N-130-000 systemd[1]: Started Process Core Dump (PID 36687/UID 0).
Mär 15 14:10:49 N-130-000 systemd-coredump[36688]: Removed old coredump core.xfce4-screensav.1000.8f26b36e4cd54e3685c7d421de9d1772.10029.1678709129000000.zst.
Mär 15 14:10:49 N-130-000 systemd-coredump[36688]: [🡕] Process 36655 (xfce4-screensav) of user 1000 dumped core.
Stack trace of thread 36655:
#0 0x00005607eee70f71 n/a (xfce4-screensaver-dialog + 0xef71)
#1 0x00007f9d909e0afb g_main_context_dispatch (libglib-2.0.so.0 + 0x5aafb)
#2 0x00007f9d90a3d5d9 n/a (libglib-2.0.so.0 + 0xb75d9)
#3 0x00007f9d909e00cf g_main_loop_run (libglib-2.0.so.0 + 0x5a0cf)
#4 0x00007f9d90fd8e4f gtk_main (libgtk-3.so.0 + 0x1d8e4f)
#5 0x00005607eee69208 n/a (xfce4-screensaver-dialog + 0x7208)
#6 0x00007f9d907c2790 n/a (libc.so.6 + 0x23790)
#7 0x00007f9d907c284a __libc_start_main (libc.so.6 + 0x2384a)
#8 0x00005607eee692ce n/a (xfce4-screensaver-dialog + 0x72ce)
Stack trace of thread 36656:
#0 0x00007f9d9089f0dd syscall (libc.so.6 + 0x1000dd)
#1 0x00007f9d90a31a35 g_cond_wait (libglib-2.0.so.0 + 0xaba35)
#2 0x00007f9d909aafc4 n/a (libglib-2.0.so.0 + 0x24fc4)
#3 0x00007f9d90a1043e n/a (libglib-2.0.so.0 + 0x8a43e)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36658:
#0 0x00007f9d908999df __poll (libc.so.6 + 0xfa9df)
#1 0x00007f9d90a3d53f n/a (libglib-2.0.so.0 + 0xb753f)
#2 0x00007f9d909e00cf g_main_loop_run (libglib-2.0.so.0 + 0x5a0cf)
#3 0x00007f9d90c41e4c n/a (libgio-2.0.so.0 + 0x10fe4c)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36666:
#0 0x00007f9d9089f0dd syscall (libc.so.6 + 0x1000dd)
#1 0x00007f9d90a31ff3 g_cond_wait_until (libglib-2.0.so.0 + 0xabff3)
#2 0x00007f9d909aaf93 n/a (libglib-2.0.so.0 + 0x24f93)
#3 0x00007f9d90a10fbb n/a (libglib-2.0.so.0 + 0x8afbb)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36657:
#0 0x00007f9d908999df __poll (libc.so.6 + 0xfa9df)
#1 0x00007f9d90a3d53f n/a (libglib-2.0.so.0 + 0xb753f)
#2 0x00007f9d909de382 g_main_context_iteration (libglib-2.0.so.0 + 0x58382)
#3 0x00007f9d909de3d2 n/a (libglib-2.0.so.0 + 0x583d2)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
ELF object binary architecture: AMD x86-64
Mär 15 14:10:49 N-130-000 systemd[1]: systemd-coredump@50-36687-0.service: Deactivated successfully.
Mär 15 14:11:20 N-130-000 systemd[1]: lightdm.service: Main process exited, code=killed, status=9/KILL
Mär 15 14:11:20 N-130-000 at-spi-bus-launcher[32927]: X connection to :0 broken (explicit kill or server shutdown).
#: coredumpctl info 36655
PID: 36655 (xfce4-screensav)
UID: 1000 (user-01)
GID: 1000 (user-01)
Signal: 11 (SEGV)
Timestamp: Wed 2023-03-15 14:10:49 CET (53min ago)
Command Line: /usr/lib/xfce4-screensaver-dialog --monitor=1 --height=1440 --width=2560 --enable-switch
Executable: /usr/lib/xfce4-screensaver-dialog
Control Group: /user.slice/user-1000.slice/user@1000.service/session.slice/dbus.service
Unit: user@1000.service
User Unit: dbus.service
Slice: user-1000.slice
Owner UID: 1000 (user-01)
Boot ID: 650aa5ec6c0d4739b637fa3f9acda353
Machine ID: 2ca0ebf359984bcabb873303155f164f
Hostname: N-130-000
Storage: /var/lib/systemd/coredump/core.xfce4-screensav.1000.650aa5ec6c0d4739b637fa3f9acda353.36655.1678885849000000.zst (present)
Size on Disk: 24.7M
Message: Process 36655 (xfce4-screensav) of user 1000 dumped core.
Stack trace of thread 36655:
#0 0x00005607eee70f71 n/a (xfce4-screensaver-dialog + 0xef71)
#1 0x00007f9d909e0afb g_main_context_dispatch (libglib-2.0.so.0 + 0x5aafb)
#2 0x00007f9d90a3d5d9 n/a (libglib-2.0.so.0 + 0xb75d9)
#3 0x00007f9d909e00cf g_main_loop_run (libglib-2.0.so.0 + 0x5a0cf)
#4 0x00007f9d90fd8e4f gtk_main (libgtk-3.so.0 + 0x1d8e4f)
#5 0x00005607eee69208 n/a (xfce4-screensaver-dialog + 0x7208)
#6 0x00007f9d907c2790 n/a (libc.so.6 + 0x23790)
#7 0x00007f9d907c284a __libc_start_main (libc.so.6 + 0x2384a)
#8 0x00005607eee692ce n/a (xfce4-screensaver-dialog + 0x72ce)
Stack trace of thread 36656:
#0 0x00007f9d9089f0dd syscall (libc.so.6 + 0x1000dd)
#1 0x00007f9d90a31a35 g_cond_wait (libglib-2.0.so.0 + 0xaba35)
#2 0x00007f9d909aafc4 n/a (libglib-2.0.so.0 + 0x24fc4)
#3 0x00007f9d90a1043e n/a (libglib-2.0.so.0 + 0x8a43e)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36658:
#0 0x00007f9d908999df __poll (libc.so.6 + 0xfa9df)
#1 0x00007f9d90a3d53f n/a (libglib-2.0.so.0 + 0xb753f)
#2 0x00007f9d909e00cf g_main_loop_run (libglib-2.0.so.0 + 0x5a0cf)
#3 0x00007f9d90c41e4c n/a (libgio-2.0.so.0 + 0x10fe4c)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36666:
#0 0x00007f9d9089f0dd syscall (libc.so.6 + 0x1000dd)
#1 0x00007f9d90a31ff3 g_cond_wait_until (libglib-2.0.so.0 + 0xabff3)
#2 0x00007f9d909aaf93 n/a (libglib-2.0.so.0 + 0x24f93)
#3 0x00007f9d90a10fbb n/a (libglib-2.0.so.0 + 0x8afbb)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
Stack trace of thread 36657:
#0 0x00007f9d908999df __poll (libc.so.6 + 0xfa9df)
#1 0x00007f9d90a3d53f n/a (libglib-2.0.so.0 + 0xb753f)
#2 0x00007f9d909de382 g_main_context_iteration (libglib-2.0.so.0 + 0x58382)
#3 0x00007f9d909de3d2 n/a (libglib-2.0.so.0 + 0x583d2)
#4 0x00007f9d90a0e7c5 n/a (libglib-2.0.so.0 + 0x887c5)
#5 0x00007f9d90824bb5 n/a (libc.so.6 + 0x85bb5)
#6 0x00007f9d908a6d90 n/a (libc.so.6 + 0x107d90)
ELF object binary architecture: AMD x86-64
1 Like
i do not see the issue here on 3 machines and also not in vms.
but xfce4-screensaver … its not really modern … all together with general lock/powersaving settings on xfce4…
thats not only on xfce4 … i saw this also using gnome p.e. and same counts for light-locker… it will only work properly if nothing else sets these values…
This might be useful for upstream xfce devs.
Sadly I am not that of an expert 
.
AFAIK and IIRC, some DEs (or systemd?) can handle these conflicts and won’t start an overlapping service. As you said, xfce is old and more free (allowing?) than others, so conflicts should be handled by the user (maybe?).
1 Like
but … i like to get you in on complicated cases… always brings in a clear view … and i believe you are an expert.
1 Like
would be the place to report…
There are several issues about the subject at xfce gitlab.
A nice one is this.
There is also a possible conflict with the autostarted programs (similar/same filenames).
Affected users might want to check which relevant programs (xflock, xfce-screensaver, xscreensaver, light-locker, etc.) are autostarted, and/or running in the session.
Maybe with
pgrep -a lock
pgrep -a saver
1 Like
if so mostt of them will be in /etc/xdg/autostart/
For me downgrading both
glib2 from 2.76.0-1 to 2.74.6-1
accountsservice from 22.08.8-3 to 22.08.8-2
fixes the issue
I updated glib2 on February 12 and accountsservice on February 13. On February 13 I noticed the issue described and first attempted to downgrade all packages I updated on the 13th. Nothing changed so I looked at the 12th and glib2 stood out so I downgraded that package and upgraded the packages from the 13th one by one until the problem showed up. The first package I upgraded ‘accountsservice’ broke my system so I surmised that the combination of glib2 and accountsservice was the culprit. I have since tested this ‘fix’ (downgrading both glib2 and accountsservice) on 3 laptops and 2 VM’s and the lock issue is fixed on all 5 systems. Note that 2 of the systems do not use xfcescreensaver, but all 5 use xflock4. Quickly tested by ctrl+alt+L to lock the system.
Today I noticed that accounsservice had an upgrade available (22.08.8-4) I tested in a VM if upgrading glib2 (2.76.0-1) and accountsservice (22.08.8-4) would fix this issue. It does not.
To summarize:
glib2 2.76.0-1 and accountsservice >= 22.08.8-3 cause the issue
glib2 2.74.6-1 and accountsservice 22.08.8.2 work fine
side note: to quickly downgrade a package use ‘sudo downgrade glib2 accountsservice’ to persist the downgrade add to /etc/pacman.conf (uncomment the line)
IgnorePkg = glib2 accountsservice
when permanent fix becomes available just comment the IgnorePkg line (should be commented by default)
1 Like
Your solution works for me:
- Downgrade to
glib2 2.74.6-1 - Downgrade to
accountsservice 22.08.8-2
Thank you!
Why do you think you were having the same issue?
What common system component do you have with the other posters’ systems?
This issue has become confusing IMHO, since random users with unknown systems post random experience.
I would suggest anyone that believes they have this issue, post system info, so we talk the same.
At least:
inxi -SMaz
pacman -Qs screensaver
pacman -Qs locker
pacman -Qs xfce
Also, part of journal log from a failing boot session might help (knowing we are talking about the same issue ).
FWIW, accountsservice is related to lightdm (not locking or screensaving) and merged support for lightdm recently.
For me, I don’t use XFCE as a DE. I only start xfce4-power-manager which starts xfce4-screensaver and xfconfd. And to rehash, when xfce4-screensaver is set to lock, I have the flashing problem.
I don’t use lightdm, doing xinit to login. So the locked screensaver is my only experience with this flashing issue.
I had this problem after my Sunday update, where I did get a new glib2 package. I did not get accountservice until a Monday update. I’d bet it’s just glib2, but don’t have time to try until later this week or weekend. If someone else has the time and experience level, would be interested to see.
For my screensaver needs, I’ve disabled my xfce4-power-manager and installed/using xscreensaver. MUCH better screensavers!! Screen DPMS, and screen locking! 
1 Like