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HermannSW
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Location: Eberbach, Germany
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Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 8:43 am

Hi,

last night I pressed Fn+F10 to power down my Pi400 -- all was fine at that point in time.
Today I powered on the Pi400, and the Desktop menu is gone.
Difficult to use at all.
I did CTRL+ALT+F2 to open console, logged in and executed:

Code: Select all

DISPLAY=:0 lxterminal
Then I switched back to X11 with CTRL+ALT+F7.
In terminal I used raspi2png to create screenshot below.

I really would appreciate to get my desktop back without reinstalling.
Any help is appreciated.

Content of ~/.xsession-errors:

Code: Select all

Xsession: X session started for pi at Sat 25 Sep 2021 02:15:58 AM CEST
dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
dbus-update-activation-environment: setting DISPLAY=:0
dbus-update-activation-environment: setting XAUTHORITY=/home/pi/.Xauthority
localuser:pi being added to access control list
dbus-update-activation-environment: setting GTK_MODULES=gail:atk-bridge
dbus-update-activation-environment: setting QT_ACCESSIBILITY=1
dbus-update-activation-environment: setting USER=pi
dbus-update-activation-environment: setting LANGUAGE=en_US.UTF-8
dbus-update-activation-environment: setting TEXTDOMAIN=Linux-PAM
dbus-update-activation-environment: setting XDG_SESSION_TYPE=x11
dbus-update-activation-environment: setting HOME=/home/pi
dbus-update-activation-environment: setting DESKTOP_SESSION=lightdm-xsession
dbus-update-activation-environment: setting XDG_SEAT_PATH=/org/freedesktop/DisplayManager/Seat0
dbus-update-activation-environment: setting GTK_MODULES=gail:atk-bridge
dbus-update-activation-environment: setting DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/1000/bus
dbus-update-activation-environment: setting LOGNAME=pi
dbus-update-activation-environment: setting XDG_SESSION_CLASS=user
dbus-update-activation-environment: setting PATH=/home/pi/.cargo/bin:/home/pi/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/local/games:/usr/games
dbus-update-activation-environment: setting XDG_SESSION_PATH=/org/freedesktop/DisplayManager/Session0
dbus-update-activation-environment: setting XDG_RUNTIME_DIR=/run/user/1000
dbus-update-activation-environment: setting DISPLAY=:0
dbus-update-activation-environment: setting LANG=en_US.UTF-8
dbus-update-activation-environment: setting XDG_SESSION_DESKTOP=lightdm-xsession
dbus-update-activation-environment: setting XAUTHORITY=/home/pi/.Xauthority
dbus-update-activation-environment: setting XDG_GREETER_DATA_DIR=/var/lib/lightdm/data/pi
dbus-update-activation-environment: setting SHELL=/bin/bash
dbus-update-activation-environment: setting GDMSESSION=lightdm-xsession
dbus-update-activation-environment: setting QT_ACCESSIBILITY=1
dbus-update-activation-environment: setting GPG_AGENT_INFO=/run/user/1000/gnupg/S.gpg-agent:0:1
dbus-update-activation-environment: setting LC_ALL=en_US.UTF-8
dbus-update-activation-environment: setting PWD=/home/pi
** Message: 02:15:59.064: main.vala:101: Session is LXDE-pi
** Message: 02:15:59.065: main.vala:102: DE is LXDE
** Message: 02:15:59.465: main.vala:133: log directory: /home/pi/.cache/lxsession/LXDE-pi
** Message: 02:15:59.465: main.vala:134: log path: /home/pi/.cache/lxsession/LXDE-pi/run.log
snapshot.png.33%.jpg
snapshot.png.33%.jpg
snapshot.png.33%.jpg (17.12 KiB) Viewed 479 times
https://github.com/Hermann-SW/memrun
https://stamm-wilbrandt.de/2wheel_balancing_robot
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/en/Raspberry_camera.html

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kerry_s
Posts: 2381
Joined: Thu Jan 30, 2020 7:14 pm

Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 12:25 pm

in that terminal, launch pcmanfm, in pcmanfm> go> applications> preferences> appearance settings, default tab medium
then reboot
Attachments
2021-09-25-022455_1920x1080_scrot.png
2021-09-25-022455_1920x1080_scrot.png (174.05 KiB) Viewed 408 times

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HermannSW
Posts: 4608
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
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Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 1:38 pm

Thanks, I followed your instructions.
But after reboot I get the same situation where I posted the screenshot.
The grey bar at top of screen is empty, no menu, ... :-(

Besides the question how to fix this -- how can this situation be caused by powering down Pi400 with Fn+F10?
https://github.com/Hermann-SW/memrun
https://stamm-wilbrandt.de/2wheel_balancing_robot
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/en/Raspberry_camera.html

GlowInTheDark
Posts: 2035
Joined: Sat Nov 09, 2019 12:14 pm

Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 1:43 pm

Check to see if you have a process named "lxpanel" running. My guess is you don't. (The point being that you should...)

I have this problem from time to time - where lxpanel crashes and the menu bar goes away. Sometimes (rarely), you can restart lxpanel and it will work, but usually, it just keeps crashing until you reboot.

But I'm surprised that, in your case, rebooting seems to not fix it. Is there any way you could rig up your startup sequence to check to see if lxpanel is running at any point and, if so, when/how it crashes?
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HermannSW
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Location: Eberbach, Germany
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Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 4:57 pm

Thank you!
lxpanel was not running.

When I start lxpanel it lives at bottom of display and looks different.
In panel setting I did choose top edge, and system theme -- then it looked as I remebered it.
Finally adding Network status monitor applet makes it look good.

A lot of hits for lxpanel in /etc/xdg -- what is the typical startup for lxpanel during boot process?

Code: Select all

find /etc -type f -exec grep -nH lxpanel {} \;
https://github.com/Hermann-SW/memrun
https://stamm-wilbrandt.de/2wheel_balancing_robot
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/en/Raspberry_camera.html

GlowInTheDark
Posts: 2035
Joined: Sat Nov 09, 2019 12:14 pm

Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 5:51 pm

Well, OK - sounds like we have a solution!

Normally, lxpanel runs as: lxpanel --profile LXDE-pi


You could try killing the one that is running, and then running the above command from a shell prompt.

Unfortunately, I have no idea where/how it gets run (launched) during system startup. Sounds like something got broke in your configuration.

The usual advice applies: Try flashing a fresh image onto a new SD card and boot that. You should then see lxpanel running normally, and you can verify that it is running as shown above.
Poster of inconvenient truths.

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"nokcid" wants to date me.

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HermannSW
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Location: Eberbach, Germany
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Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 7:08 pm

GlowInTheDark wrote:
Sat Sep 25, 2021 5:51 pm
Normally, lxpanel runs as: lxpanel --profile LXDE-pi
I killed the lxpanel running and started that command -- it asserts, that is the reason lxpanel does not show correct after reboot. Maybe fresh image is needed ...

Code: Select all

pi@raspberrypi400:~/memrun/C $ lxpanel --profile LXDE-pi
** Message: 12:47:58.997: x-terminal-emulator has very limited support, consider choose another terminal
grep: /home/pi/.config/lxpanel/LXDE-pi/panels/*: No such file or directory
** Message: 12:47:59.351: Connecting ...
** Message: 12:47:59.351: Status changed to down

** (lxpanel:25875): WARNING **: 12:47:59.441: init context: err:6 Connection refused

Assertion 'pthread_mutex_lock(&m->mutex) == 0' failed at pulsecore/mutex-posix.c:90, function pa_mutex_lock(). Aborting.
Aborted
pi@raspberrypi400:~/memrun/C $ 
https://github.com/Hermann-SW/memrun
https://stamm-wilbrandt.de/2wheel_balancing_robot
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/en/Raspberry_camera.html

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HermannSW
Posts: 4608
Joined: Fri Jul 22, 2016 9:09 pm
Location: Eberbach, Germany
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Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 7:26 pm

The error message stated that panels directory had no file.
I took micro SD card from a Pi4B and copied these two files over to my Pi400:

Code: Select all

$ find .config/lxpanel/LXDE-pi/
.config/lxpanel/LXDE-pi/
.config/lxpanel/LXDE-pi/panels
.config/lxpanel/LXDE-pi/panels/panel
.config/lxpanel/LXDE-pi/config
$

After reboot panel is fine ... only issue left seems to be that the time is not correct despite internet connectivity.
https://github.com/Hermann-SW/memrun
https://stamm-wilbrandt.de/2wheel_balancing_robot
https://stamm-wilbrandt.de/en#raspcatbot
https://github.com/Hermann-SW/Raspberry_v1_camera_global_external_shutter
https://stamm-wilbrandt.de/en/Raspberry_camera.html

GlowInTheDark
Posts: 2035
Joined: Sat Nov 09, 2019 12:14 pm

Re: Lost X11 Desktop partially -- how to get it back?

Sat Sep 25, 2021 7:30 pm

Interesting.

I have learned something from this thread.
Poster of inconvenient truths.

Linux zealot and proud of it.

"nokcid" wants to date me.

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