Reading other threads, I think this is a windows issue with native instruments. Here is a workaround until they come up with a solution.
"You need to install Sublab, inside the Native Instruments VST folder, in my case it was ;
C:\Program Files\Native Instruments\VSTPlugins 64 bit
It seems that Maschine/KK only recognizes VST2 (sublab.dll).
I highly suggest that people install the VST2 in the Native Instruments folder and leave the VST3 in the standard folder."