Not sure what you are doing but I do exactly the same thing no issue. I drag form scaler straight onto a midi track with a loaded Komplete Kontrol instrument. Do it all from scratch. Open a new Ableton session and load only scaler and KK with an instrument loaded into KK. play some notes from KK to ensure you are hearing the instrument. Drag chords from scaler straight onto the KK midi track and hit the play button.
I presume you are using Ableton 64 bit.