When I open System Preferences (version 14.0) and then click on Security & Privacy, I get a popup error message:

Preferences Error
There was an error in Security & Privacy preferences.

I am using macOS Sierra Version 10.12.4 (16E195) on MacBook Air (Early 2014), 1.4 GHz Intel Core i5, 4 GB 1600 MHz DDR3, Intel HD Graphics 5000 1536 MB

System Preferences info:

Version:    14.0
Obtained from:    Apple
Last Modified:    4/12/17, 18:59
Kind:    Intel
64-Bit (Intel):    Yes
Signed by:    Software Signing, Apple Code Signing Certification Authority, Apple Root CA
Location:    /Applications/System Preferences.app

I've changed the language setting, time setting, etc. over the course of use. I don't know much about programming, but I've used Terminal to change some settings manually. I've also deleted some files I needed a password to delete, to get rid of iTunes. Because I felt like it. I've logged in on another account on the same MacBook, and encountered the same issue with System Preferences > Security & Privacy.

I've already tried restarting, logging in/out. I've also noticed that I seem to be able to open any other icon in system preferences. The issue seems likely not my fault, given it is on both accounts. It is good to note that I've used command line to try to reveal hidden files and stuff, but I don't think that's it.

I was, in both logins, in an admin account with a password.
This is the Console error:

error   10:53:05.711585 -0700   accountsd   "ACDAuthenticationPluginManager: an authentication plugin of class (null) for auth type <private> could not be instantiated! Load Error: (null)"
error   10:53:05.711666 -0700   accountsd   "The authentication plugin for account <private> could not be found!"
error   10:53:05.946849 -0700   accountsd   "ACDAuthenticationPluginManager: an authentication plugin of class (null) for auth type <private> could not be instantiated! Load Error: (null)"
error   10:53:05.946930 -0700   accountsd   "The authentication plugin for account <private> could not be found!"
error   10:53:06.046644 -0700   accountsd   "ACDAuthenticationPluginManager: an authentication plugin of class (null) for auth type <private> could not be instantiated! Load Error: (null)"
error   10:53:06.046796 -0700   accountsd   "The authentication plugin for account <private> could not be found!"
error   10:53:06.075493 -0700   com.apple.preference.security.remoteservice <private>
error   10:53:06.077179 -0700   com.apple.preference.security.remoteservice <private>
error   10:53:06.096064 -0700   sharingd    SDConnectionManager:: XPC connection invalidated
error   10:53:06.127294 -0700   ReportCrash Failed to start process notifications for pid 674 (16)

I also looked at some stuff in Terminal:

$ ls /Library/Preferences/com.apple.se*
/Library/Preferences/com.apple.security.appsandbox.plist
/Library/Preferences/com.apple.security.plist
/Library/Preferences/com.apple.security.systemidentities.plist

I tried the reply marked Solved by Maxym on "Security & Privacy preference pane Error Mavericks" but clients.plist did not dissapear:

Last login: Sun May 21 12:03:18 on ttys000
talib7@Elizabeths-MacBook-Air:~$ sudo -s
Password:
root@Elizabeths-MacBook-Air:~$ cd /var/db/locationd/
root@Elizabeths-MacBook-Air:/var/db/locationd$ ls -al
total 32
drwxr-x--- 5 _locationd _locationd 170 May 21 12:18 .
drwxr-xr-x 82 root wheel 2788 May 21 10:09 ..
drwx------ 4 _locationd _locationd 136 Sep 23 2014 Library
-rw-r--r-- 1 _locationd _locationd 5226 May 21 12:18 clients.plist
-rw-r--r-- 1 root _locationd 5000 May 21 10:45 clients.plist.saved
root@Elizabeths-MacBook-Air:/var/db/locationd$ killall locationd && rm clients.plist && killall locationd
root@Elizabeths-MacBook-Air:/var/db/locationd$ ls -al
total 32
drwxr-x--- 5 _locationd _locationd 170 May 21 12:28 .
drwxr-xr-x 82 root wheel 2788 May 21 10:09 ..
drwx------ 4 _locationd _locationd 136 Sep 23 2014 Library
-rw-r--r-- 1 _locationd _locationd 5226 May 21 12:28 clients.plist
-rw-r--r-- 1 root _locationd 5000 May 21 10:45 clients.plist.saved
root@Elizabeths-MacBook-Air:/var/db/locationd$ killall locationd && rm clients.plist && killall locationd
No matching processes were found
root@Elizabeths-MacBook-Air:/var/db/locationd$ ls -al
total 32
drwxr-x--- 5 _locationd _locationd 170 May 21 12:28 .
drwxr-xr-x 82 root wheel 2788 May 21 10:09 ..
drwx------ 4 _locationd _locationd 136 Sep 23 2014 Library
-rw-r--r-- 1 _locationd _locationd 5270 May 21 12:28 clients.plist
-rw-r--r-- 1 root _locationd 5000 May 21 10:45 clients.plist.saved
root@Elizabeths-MacBook-Air:/var/db/locationd$ killall locationd && cp clients.plist.saved clients.plist && killall locationd
root@Elizabeths-MacBook-Air:/var/db/locationd$ ls -al
total 32
drwxr-x--- 5 _locationd _locationd 170 May 21 12:28 .
drwxr-xr-x 82 root wheel 2788 May 21 10:09 ..
drwx------ 4 _locationd _locationd 136 Sep 23 2014 Library
-rw-r--r-- 1 _locationd _locationd 5270 May 21 12:28 clients.plist
-rw-r--r-- 1 root _locationd 5000 May 21 10:45 clients.plist.saved