Downstream report: https://bugzilla.redhat.com/show_bug.cgi?id=1729059 Basically if you login and then immediately logout you get a dialog with: Received error while trying to log out GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: Type of message, "(yb)", does not match expected type "(b)"
I tried to reproduce this issue, but without success. In a second test I even used an autostart launcher to immediately trigger the logout. xfce4-session 4.14.2
Closing this report.