Certain applications stopped showing their indicators in indicators tray in GNOME 3
Probably after I have installed something, certain application (VLC, ownCloud client) do not display their indicators in the indicators tray of GNOME 3 shell any more. Others (GNOME Do, Skype) still show their indicators. This is on Ubuntu GNOME 16.04.1.
What could be the reason that VLC and ownCloud indicators do not show up any more? How can I fix this?