Error message

just updated my system and all works well but journalctl -p 3 -b
shows me a new error
cinnamon-session[1246]: GLib-CRITICAL: t+0.81955s: g_child_watch_add_full: assertion ‘pid > 0’ failed

is this something to be concerned about?

There is a similar report on Arch forum (in German):

You might want to keep an eye on that as well while waiting for others to reply here.

interesting enough i had a cinnamon update as well