TigerVNC server not working after do_release_upgrade to 22.04.4 LTS

[Bo Berglund]

I have an HP workstation laptop on which I have run 20.04 for a few years.
The laptop mostly sits with closed lid in a cupboard and I access it using VNC
and PuTTY from Windows.
It is mainly used as a machine performing time scheduled tasks like video
transfers.

Today I bit the bullet and launched the upgrade to 22.04.4 using the
do-release-upgrade command, using PuTTY in an SSH shell from Windows 10.

All seemed to work fine and after some half hour or so it was done and requested
to be allowed to reboot.

After the reboot I could log back on with PuTTY just fine and it is now running
the latest 22.04.4.


But I also have some development software on this machine which I need to access
on a GUI screen so I use TigerVNC for that since several years.

After the upgrade/reboot I can no longer access the VNC functionality!
The client  (RealVNC-Viewer on Windows 10) just hangs and never connects, so I
checked the laptop status:
---------------------
sudo systemctl status vncserver at 1
× vncserver at 1.service - Systemd TigerVNC server startup script for Ubuntu 20.04
     Loaded: loaded (/etc/systemd/system/vncserver at .service; enabled; vendor
preset: enabled)
     Active: failed (Result: exit-code) since Wed 2024-03-20 09:25:51 CET; 18min
ago
    Process: 1213 ExecStartPre=/usr/bin/vncserver -kill :1 &> /dev/null
(code=exited, status=255/EXCEPTION)
    Process: 1290 ExecStart=/usr/bin/vncserver -depth 24 -localhost no -geometry
1680x1040 :1 (code=exited, status=255/EXCEPTION)
        CPU: 618ms

mar 20 09:25:51 auriga-ubuntu vncserver[1302]:
==================================================================================>
mar 20 09:25:51 auriga-ubuntu vncserver[1302]: Session startup via
'/home/bosse/.vnc/xstartup' cleanly exited too early (< 3 seco>
mar 20 09:25:51 auriga-ubuntu vncserver[1302]: Maybe try something simple first,
e.g.,
mar 20 09:25:51 auriga-ubuntu vncserver[1302]:         tigervncserver -xstartup
/usr/bin/xterm
mar 20 09:25:51 auriga-ubuntu dbus-daemon[1316]: [session uid=1000 pid=1313]
AppArmor D-Bus mediation is enabled
mar 20 09:25:51 auriga-ubuntu vncserver[1302]: The X session cleanly exited!
mar 20 09:25:51 auriga-ubuntu vncserver[1302]: Killing Xtigervnc process ID
1303... success!
mar 20 09:25:51 auriga-ubuntu systemd[1]: vncserver at 1.service: Control process
exited, code=exited, status=255/EXCEPTION
mar 20 09:25:51 auriga-ubuntu systemd[1]: vncserver at 1.service: Failed with
result 'exit-code'.
mar 20 09:25:51 auriga-ubuntu systemd[1]: Failed to start Systemd TigerVNC
server startup script for Ubuntu 20.04.
lines 1-17/17 (END)
---------------------

Then I tried to start it:
---------------------
$ sudo systemctl start vncserver at 1
Job for vncserver at 1.service failed because the control process exited with error
code.
See "systemctl status vncserver at 1.service" and "journalctl -xeu
vncserver at 1.service" for details.
---------------------

What can be the cause for this and how can I remedy it?
I found this online:
https://askubuntu.com/questions/1425048/vnc-server-not-working-since-ubuntu-22-04-upgrade
and the symptoms are the same, but there is no solution posted there...



-- 
Bo Berglund
Developer in Sweden