If a server-side method wrapped with the GLib bindings receives a message marked with the noreply flag, a reply is sent anyway. This then confuses the client as there is no pending reply for the message reply that arrives, so it sends back an error (AccessDenied specifically).
glib bindings should do this, but it should not confuse the client if it gets an error or reply without a pending reply, so robustness against that is another bug to fix. (The bus sending accessdenied is correct I think, but the sender of the reply should just ignore this error)
I missed this earlier bug when filing bug 19441, which is now fixed. *** This bug has been marked as a duplicate of bug 19441 ***
Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.