Changes in NM lately (I suppose https://github.com/NetworkManager/NetworkManager/commit/4672499b95083d2f4b38ec9f409d72c74ade2902) changed the dbus initialization order. This results in multiple errors like No such interface 'org.freedesktop.NetworkManager.AgentManager' on object at path /org/freedesktop/NetworkManager/AgentManager in the dbus traffic from kded on the system bus. The result is in this case a missing secret agent.
Attempt at fixing this: https://phabricator.kde.org/D16471
Just want to chime and confirm I have this exact issue with kde 5.51.0 / Qt 5.11.2 plasma-nm 5.14.2 / NetworkManager 1.14.0, on OpenSUSE. Happens everytime NM is restarted, which in my case happens when I update the package. I've had this issue for a while now. Also seems like #398524 is the same issue.
Git commit fa472e6a5e2637a681f61e75cf0988bf847f46ed by Fabian Vogt. Committed on 06/11/2018 at 19:17. Pushed by fvogt into branch 'master'. Listen for added DBus interfaces instead of registered services Summary: When the service is registered, the interfaces might not be available yet. So wait for those instead. This was RFC because: - I'm not sure whether it's guaranteed that InterfacesAdded is emitted on service registration as well or both connections are necessary - I don't know how it's possible to test this as org.kde.fakenetwork does not support the org.freedesktop.ObjectManager API Test Plan: Restarting NM while kded5 keeps running caused "nmcli up" to fail because of missing secrets. With this patch, it works successfully. Reviewers: #frameworks, jgrulich Reviewed By: jgrulich Subscribers: kde-frameworks-devel Tags: #frameworks Differential Revision: https://phabricator.kde.org/D16471 M +16 -8 src/manager.cpp M +3 -1 src/manager_p.h M +12 -3 src/secretagent.cpp M +1 -0 src/secretagent.h M +1 -1 src/secretagent_p.h https://commits.kde.org/networkmanager-qt/fa472e6a5e2637a681f61e75cf0988bf847f46ed