error on system preferences desktop and screen saver

Open Finder in the Dock>click on "Library" in the left hand column">click on "Preferences" in the next column over>expand the "Preferences" column by clicking on the single column button at the top of the window, and click on the line "com.apple.systempreferences.plist" to highlight it, and then drag it to the Trash, to clear that Preferences file and reset it. That should solve your problem.

Try this option: Could not load Energy Saver preference pane. Scroll down to the solution that references opening system preferences in 32 bit mode. Worked wonders for me.