FLstudio on macOS X and this functionality seems does not works here. It only works for native FLstudio plugins like 3x Osc, EQ etc. Do you have an idea how to set this things to work on the system ...
Most of Useful VST comes with .NKI extension types so i request the FL Team to make it support .NKI format too so that we doesnot have to rely on other vst like Kontakt. ...