How to remove a corrupted Trust Settings Record?
I finally found the Admin trust settings. It's in a file called Admin.plist
in the /Library/Security/Trust Settings directory. Deleting this file cleared the error!

There are other files in that directory that are named &lt;UUID&gt;.plist, where UUID is the value of the GeneratedUID key in the user record. You can see this value with this command:

dscl . cat /Users/&lt;short login name&gt; GeneratedUID`


These files store the per-user trust settings.