I've had this problem since 6.8, and I don't want to have to revert back to 6.7. I've tried running all executables as administrator to no avail.
If I am right, this settings has been removed and forced to using Elevated right to run PL, but somehow it is still showing on the UI.
You can just check for it by using Process Explorer or Windows Task Manager(by showing the "Elevated" column on the detail tab). :)
BenYeeHua is right.
This setting is now always ON, no matter what it may show in the menu.
I see (now) that a vestige of it is still buried in the Options menu. I'm removing that menu item now.