KDE: Power Management configuration module could not be loaded
Fedora 21 with KDE5 turns screen off after 5 minutes. I want to increase this time. There is a menu in System Settings: Power Management. This menu should control screen turnoff. But it is blocked. It is written there:
"Power Management configuration module could not be loaded. The Power Management Service appears not to be running. This can be solved by starting or scheduling it inside ''Startup and Shutdown''.
But the "Power Management Service" in ''Startup and Shutdown' is running.
I googled this and found this is a very common bug across many distros. No solution worked for me. There's an avdice about upower -- yes, I see upower at my system, but this doesn't help.
Please help me with getting KDE's Power Management configuration to work and not to turn off monitor after every 5 minutes.