How to reset the AU validation.

Digital Performer:
Trash the "Audio Unit Info Cache" file and then relaunch Digital Performer:
Macintosh HD / Users / 'Your Account' / Library / Preferences / Digital Performer™ / Audio Unit Info Cache

Logic Pro:
Go to the Logic application menu > Preferences > Start > Logic AU Manager.
Find the plugin in the list and click on the "Rescan" button.