If you are getting this error message in Kontakt when trying to add a new library, you may have a Spitfire Audio product that does not support adding the library to Kontakt.
Many of our products are "Player" libraries, that means they will work in Kontakt Player and can be added as libraries.
However, there are also many products that we sell that will only work in the FULL version of Kontakt and cannot be added as libraries. These products will need to be loaded via the Kontakt files browser or alternatively you can add the library as a favourite to the Kontakt Quick Load window.
If you have any of our Player libraries you can qualify for a discount on the full version of Kontakt see HERE for more information.