Comment # 3 on bug 934162 from Guido Berhoerster

(In reply to Raymond Wooninck from comment #2)
> Given the user is using Tumbleweed, all KDE applications definitely switched
> to Plasma5, which also has the switch regarding the systray icons.  Plasma5
> is no longer Xembed based, but on StatusNotifier. 
> 
> My guess is that XFCE4 for the user is setup that the systray only shows the
> XEmbed based icons in its systray.
> 
> Googling delivered me the following post for Xubuntu that describes a
> similar issue: 
> https://pseudomorph.wordpress.com/2014/05/08/xfce-notification-a/
> 
> Of course the solution described here will not work for the user, but
> replacing the Notification Area applet with the Indicator Plugin applet
> should restore all required items. 
> 
> I do not know if the Indicator Plugin applet is part of the openSUSE XFCE

The Xfce indicator applet is not packaged for openSUSE and I don't see how it
would help here since it only seems to be designed to display Ubuntu's
messaging menu. Xfce still relies on Xembed systray, but this is not the
problem here at all.

> desktop, but this is not a KDE/Plasma bug. Apologies for reassigning the bug
> back to the XFCE group, but there is nothing that can be done from a
> KDE/Plasma perspective as this is working as designed. XFCE System Tray
> would need to pick up those icons that are using the StatusNotifier (which
> apparently can do through this Indicator Plugin Applet).

That is completely wrong, the KStatusNotifier widget automatically falls back
to a QSystemTrayIcon if status notifiers are not available. Please read the
above bug report and look at the screenshot (or check the code), klipper
actually falls back to a QSystemTrayIcon widget, but does not set an icon for
it and Qt logs a warning about that when the setVisible method is called. So
clearly the fallback is not working as intended, either because the icon cannot
be loaded for some reason or because of some issue with the fallback code in
the KDE Frameworks.