Yesterday I had to erase and restore (I goofed somewhere)
Was that done using Time Machine... or how?
and for some reason I'm not aware of, my system prefs would not open.
Which method are you using to open them (i can think of three), and what all *does* happen when you try it that way?
Does the same mode of failure occur if you open the /Applications folder and directly double-click on System Preferences.app?
Here are some caches & plists to trash: