All of our instruments that are powered by the Kontakt engine require authorization by Native Instruments. You'll need to install their content management software, Native Access. Add your library to Kontakt by clicking the “Add Library” button on the top left of the Kontakt browser, then entering your serial number when prompted. If you receive an error message, first make sure you have the latest version of Kontakt, available at the Native Instruments website. If that does not fix the issue, please contact us at: support(at)heavyocity.com.