The 6.1.1 version addressed several stability concerns from previous iterations:

Fixed unpredictable file sorting on Mac APFS drives.

A new mode for the wavetable module that stretches partials away from the harmonic series, allowing for bell-like and metallic tones.

To help you further, are you looking to issue, or are you interested in developing your own instruments using the KSP and Creator Tools mentioned? See what's new in KONTAKT 6 | Native Instruments