When I login to the GUI X screen an error message appears reading "No
session for pid ...." where .... is a pid and is different for each login.
Checking on the inet found the problem reported by others but a suggested
work around didn't work for me or for someone else.   The pid always maps
to lxpolkit.  You have to click "OK" on this error message to get rid of
it.

		David Lawyer

control: reassign -1 lxpolkit

Thank you for reporting this.

Your issue seems as a lxpolkit configuration problem. Could you, please,
look if there aren't two lxpolkit processes running at the moment when
you are logged in?
Could you also check if there is a policy kit agent checked on in the
list of autostarted processes? You can see that in lxsession default apps
configuration program on tab 'Autostart'. If it's checked on then please,
check it off and then report if it fixes the issue. Thank you in advance.

The problem is still present on Debian Bullseye when simply doing "apt
install lxde" and "startx".

When additionally "apt install lxsession-default-apps", it can be seen
that "lxpolkit" is set as default "Polkit agent" and clearing that field
resolves the issue.

The thing is now that "openbox-lxde-session" ships
"/etc/xdg/lxsession/LXDE/desktop.conf" with no related entries, but when
starting a first desktop session a lot of entries are added to this
file, including "polkit/command=lxpolkit". Not sure whether this is
intended, IMHO entries should be added to the current users config only,
not to the system-wide config, and of course not
"polkit/command=lxpolkit" if it causes this conflict. I just don't know
what exactly is adding it.

On Stretch and Buster this is not an issue btw.
"polkit/command=lxpolkit" is added as well but does not cause the error
prompt.

Best regards,

Micha

Adding another information:

I retested it on Debian Buster and Stretch and the same error prompt
appears when LXDE is not started from the actual screen/console but when
calling "startx" from e.g. an SSH session, which then start LXDE on the
main screen. The solution/workaround is the same.

Interestingly there is not a single lxpolkit process running then, so it
is not a conflict between multiple lxpolkit. I'm not sure whether
disabling it completely is the right thing, respectively of any negative
impact when doing so. Probably there is something missing or lxpolkit
needs to be actively configured to work fine with LXDE?

I hope this helps to track down the issue.

Best regards,

Micha