System preferences won’t quit

Hizzonnah Said:

"System preferences won’t quit: I tried that and it told me it wouldn’t shut down because system preferences wouldn’t quit. I finally got it to shut down by holding down the on/off button. It took about 10 minutes after I did that for the computer to shut off."

-------

Boot in Safe Mode:

[Hold Down: shift key, upon boot], In Safe Mode, Login Items do not run at login, certain preferences are set aside, and damaged system files are then reset. So, once booted in to Safe Mode, wait 30 seconds, and then boot up normally seeing if you still get this error.

If an Errors...

Reinstall the macOS:

Nothing would be lost. It's just that misplaced items would be placed back to where they should be and corrupt system files would be replaced by clean files. Go Here: Reinstall macOS - Apple Support. Use the third bulleted method: [command + r]. As mentioned above, prior to the reinstallation, to prevent data loss, be sure to Back up your Mac with Time Machine, prior to the reinstall.

Hizzonnah Said:

"System preferences won’t quit: My system preferences wont quit. I’ve tried force quit and pasting .com.apple.systempreferences.plist to the desktop all to no avail. HELP!"

-------

Shut Down you Mac:

Save what need be, and then shut down your Mac though the Apple menu.

You are welcome.