I purchased the Korg Collection 4 today after seeing that Korg is listed as a NKS partner on NI's website (https://www.native-instruments.com/en/specials/komplete/this-is-nks/nks-partners/). Apparently Korg Collection 4 does not have NKS support (not a big deal really).
However, the Plugin UI's don't load in Komplete Kontrol 2.9 or 3.0
The UI's load fine in Maschine and Ableton, so this appears to be a Komplete Kontrol issue.