Mac Client, Missing SystemCACertificate.keychain file in /System/Library/Keychains

If you are familiar with Terminal and command line, open Terminal and type:

1. cd /System/Library/Keychains/
2. open SystemCACertificates.keychain 

If you’re not comfortable with the Terminal, do the following:

1. In Finder, select the “Go” menu and the menu item, “Go to Folder (Command-Shift-G)
2. Type in the following: "/System/Library/Keychains/"
3. Double-click the file “SystemCACertificates.keychain” and it will automagically import itself into your active Keychain.  (It will open up Keychain Access utility.)

Sometimes, this file is hidden and you may not be able to see it in Finder.  If this is the case, use the Terminal option above.