OS
How d I fix this error?
Could not load Users & Groups preferences pane
Actually I cannot open any of the modules inside of System Preferences.
iMac, OS X 10.10
Question marked as
First of all have you tried restarting your mac.
If that does not work try starting your mac up in Safe Mode.
How to use safe mode on your Mac – Apple Support (UK)
Safe Mode takes a long time to startup as much as 10 minutes, be patient.
See if System Preferences will open, then restart normally.