NKS packages are now running at v2.1.1 as of December 11 2017. If you want to know the versions you are running, check the downloaded ZIP file for the readme which shows the version. This is an incremental update from the big 2.1 update.
ALL NKS libraries have been updated with new tagging, some new artwork and database files and new sound preview files. It is RECOMMENDED to download and replace your existing libraries but it's up to you
All existing 2.1 users can access the latest updates for free. Just Login and go to My Downloads and you should see your previous downloads listed there. If something is not available, please let me know and I will look into it