How to fix my Applescript plugins for the Contacts application that are no longer available since 10.9 Mavericks upgrade?
1. The launch services database is screwed up
This Contacts.app launch services problem/issue might appear again after each Mac OS X update, like the 10.9.2 combo updater according to http://web.archiveorange.com/archive/v/2NbVio0gzU3nWMhAxfsk
1a. Command line fix
$ /System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -all l,s,u

In case of error messages like no such file or directory you can find the location of your lsregister with the command $ locate lsregister.
1b. OnyX fix
Or, you can run the OnyX application (version 2.8.7),
go to tab &quot;Automation&quot;.
Disable each check mark,
except for section &quot;Rebuilding&quot;,
and make sure that item &quot;LaunchServices&quot; is checked.
Finally hit the [ Execute ] button.
2. Move to new folder
You need to move your Address Book Plug-In AppleScript(s) from the old
~/Library/Address Book Plug-Ins/
/Library/Address Book Plug-Ins/

to a new location:
~/Library/Application Scripts/com.apple.AddressBook/