I just found the according .desktop file in /usr/share/gnome/autostart /gnome-wm.desktop and moved it to /usr/share/applications/gnome- wm.desktop . Now the error message is gone.
-- gnome-wm is missing a .desktop file https://bugs.launchpad.net/bugs/316958 You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-session in ubuntu. -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
