VNC server: plasmashell segmentation fault

I just installed Kubuntu 24.04.1 and tightvncserver.

This is my ~/.vnc/xstartup:

#!/bin/sh

unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
/etc/X11/xinit/xinitrc
# Assume either Gnome or KDE will be started by default when installed
# We want to kill the session automatically in this case when user logs out. In case you modify
# /etc/X11/xinit/Xclients or ~/.Xclients yourself to achieve a different result, then you should
# be responsible to modify below code to avoid that your session will be automatically killed
if [ -e /usr/bin/gnome-session -o -e /usr/bin/startkde ]; then
    vncserver -kill $DISPLAY
fi

I also tried replacing /etc/X11/xinit/xinitrc with startkde, with no difference.

When I open a VNC client on my remote machine, I see a “Plasma - The KDE Crash Handler” window that shows “We are sorry, Plasma closed unexpectedly” and under Details, it says “Executable: plasmashell PID 13,296 Signal: Segmentation fault (11)”.

Is this a known problem, what can I do?