System Settings-workspace theme non-responding

[marco07]

Hello Folks:
I have kubuntu 16.04 fully updated on my both desktop and laptop boxes. They both are working and performing well ever since i clean installed them when they came out. However it just happened that I needed to do some settings and fired up the "system settings", here i noted that under "Appearance" the "workspace theme" is non-responsive. I tried the same on my laptop, and got the exact reaction.
Anybody else experiencing such? Any ideas as to what might be wrong?
Thank you!
Edit- i have plasma 5.8.5

[Snowhog]

At hear, on my 16.04.1 installation, an Oracle VirtualBox VM, fully dist-upgraded every time I launch it, System Settings > Workspace Theme works just fine. Plasma version 5.8.5 also. Are there any other elements in System Settings that aren't working for you?

[marco07]

A Are there any other elements in System Settings that aren't working for you?

If I start off with "Workspace Theme", it lucks up all the others and non is responsive. I can still close the window though. But if I start with any other, they are responsive and work OK.