Why can I no longer open the Security & Privacy pane of System Preferences? Problem
Since April 2012, one user of my MacBook Pro can no longer load the Security &amp; Privacy pane.
When I click the icon, a sheet drops down:

Translated from Chinese to English:

Error
Cannot load System Preferences pane &quot;Security &amp; Privacy&quot;.

This is chaotic for me. Please: what has happened, and how can I fix it?
I also posted to Apple Support Communities:

Security &amp; Privacy System Preferences pane cannot open!

Environment
Lion, Mac OS X 10.7 -&gt; 10.7.1 -&gt; 10.7.2 -&gt; 10.7.3 (Build 11D50b).
I setup two users:

zoomq — my own account
wan — my wife's  account, not often used by her
zh-CN (PRC Chinese) (Mainland China, simplified characters) preferred for both users
both are administrators
install/uninstall software is all standard steps.

Troubleshooting
User zoomq can not load the pane.
Switch users, wan can open the pane without problem.
All other preference panes open and work fine.
When the problem occurs, nothing is logged. I have tried tail -f and all kinds of /var/log .log files.
I have not touched many system files.
I try remove
/Users/zoomq/Library/Preferences/com.apple.se*
com.apple.security.plist
com.apple.security.revocation.plist
com.apple.security.revocation.plist.lockfile

and rebooted, nothing changed.
$ ls /Library/Preferences/com.apple.se*
com.apple.security.appsandbox.plist
com.apple.security.plist
com.apple.security.systemidentities.plist
com.apple.servermgrd.plist

For wan, ~/Library/Preferences/
com.apple.security.* files are not present.
Try applying a combo update

You might try: 


download the most recent MacOSXUpdCombo10.7.3.dmg
log in as zoomq 
prefer British English or British
install the combination update
restart the computer, you should find 11D50d or greater 
run Software Update until all other updates are installed
prefer Chinese (simplified)
quit System Preferences
reopen System Preferences, retry the preference pane.


Background

At OS X Lion Update 10.7.3 (Client Combo) there is no hint that Apple published different downloads with identical names. Differences between 11D50b, 11D50c and 11D50d are not published by Apple. This situation surrounding 10.7.3 is most unusual.

Generally, without focus on 10.7.3: in some problem situations, people find that installation or re-installation using a combo has a positive effect. 

In this case: the b in your current installation, 11D50b, probably indicates that a combo (combination) update has been applied once already — maybe through the Software Update routines that are integral to OS X. Reapplying the same update, or a more recent build of the same update, should do no harm. 

There may be more technical ways of investigating causes of your problem. However: because the symptoms are unusual, I am inclined to suggest a combo update before anything else.