It brought back full key coloring on the virtual keyboard, a feature removed in version 5.6, making it easier to identify key switches and sample ranges at a glance.
Because Kontakt 5.6.6 is legacy software, it has strict compatibility limits with modern macOS versions. Operating System Compatibility Status Officially supported and highly stable. macOS 10.13 - 10.14 Generally compatible via legacy installers. macOS 10.15 (Catalina) kontakt 5.6.6 mac
Kontakt 5 will not run natively on M1/M2/M3 chips; it must be opened using Rosetta mode within your DAW (Digital Audio Workstation). Installation and Activation Can I update Kontakt 5.6.6 on Mac OS 10.13? - Community It brought back full key coloring on the