How can I get Launchbar to open the Wireless Diagnostic app?
I emailed the developer and got a very clear reply. The application has a white list to avoid putting unknown CoreServices into play, so the steps I took to index that folder were for naught. The 5.5.1 update to the app fixes this one tool.

If you can't update or want to learn how to index this file manually, read on...

I needed to instead use the Launchbar Custom List function to explicitly index the services I desired.



Also, the developer has a practice of updating the white list once Apple's update can be tested, so unless you need something like I did right after a new OS is released, just waiting for a LaunchBar update might also solve this problem in the future.