Bug 1634681

Description of problem:

After several hours or days, the application launcher menu in KDE stops working. That's the main menu or start menu in the bottom left corner, which is used to launch applications and to shut down the system.

Note that this behavior can be observed on computers that aren't shut down every evening. Many people leave their computers on most of the time, laptops are often hibernated before they're taken out of their docking station, to be used in another location the next day. I haven't yet figured out a specific time span after which KDE breaks.

When it happens, it's not possible to open the KDE application launcher menu at all. Nothing happens when you click on it and Alt + F1 doesn't work either.
That also means that the user cannot log out, hibernate or turn off the computer because that's all in the same menu, which is now dead.



Version-Release number of selected component (if applicable):

Fedora 27
plasmashell 5.12.4
KDE Frameworks: 5.44.0



How reproducible:

It happens when the computer is used for several days without shutting it down.



Steps to Reproduce:
1. Log into a KDE session and do your thing.
2. Don't shut down in the evening. Hibernate if necessary, to keep unsaved work and running applications.
3. At some point in time, you click on the menu button to hibernate the system because, well, maybe you're in a hurry. It doesn't work, the menu won't open.



Actual results:

The menu stops working after some time, it won't open anymore.



Expected results:

It should keep working.



Additional info:

I had previously opened Bug 1352205 because sometimes, the menu did open but the "Logout", "Shutdown" buttons stopped working - that was in Fedora 23.
Now, in Fedora 27, the whole KDE menu stops working. Those might even be two symptoms of the same bug, but I'm opening this bug report anyway since nobody commented in the old one.

As mentioned in Bug 1352205, it's still possible to log out and safely turn off the computer instead of pulling the plug - if you're able to open a terminal (Ctrl + Alt + T).
This command can be used to hibernate the system (KDE 5):
qdbus org.kde.Solid.PowerManagement /org/freedesktop/PowerManagement CanHibernate && qdbus org.kde.Solid.PowerManagement /org/freedesktop/PowerManagement Hibernate

It seems that the KDE menu is (usually) usable again after hibernating and then resuming the system. So that's a workaround. Unless the session is mysteriously lost and a new KDE session is started after login, with all previously running programs gone, which unfortunately does happen from time to time, but I suppose that's a different issue.