Running JACK with Traktor Audio 2 soundcard (WIN8)

Question

I want to send audio from the Dj-Software Traktor 2.6 to the DAW Ableton Live 8.2.2 and output it's master through my soundcard . As an audio interface I'm using Native Instrument Traktor Audio 2. For the virtual wiring the only good way seems to be using JACK audio connection kit.

In a nutshell:

--> Traktor --> Ableton --> Soundcard

Im running Jack 1.9.9 64bit on Windows 8 64bit as admin. I followed the instruction which you can find on Github:

- start qjackctl.exe and configure it the following way:

    - in Setup/Setting, use "jackd -S" at the "Server Path" item. WARNING: on Windows the "-S" parameter is *mandatory* to have the jack server correctly working!!

    - in Setup/Setting, use "portaudio" at the "Driver" item

    - in Setup/Misc, check the "Start JACK audio server at application startup" box

- quit QJACKCTL and start is again, it should now launch the jack server. Quitting QJACKCTL will now close the jack server.

Starting the jack server with another audio device installed on the machine (like an ASIO card) can now be done directly in QJACKCTL. 
A ">" button at the right of the interface button allows to list the name of all available devices, driven either by "MME", "DirectSound", or "ASIO".

But when I select "ASIO::Traktor Audio 2" from the list and restart server & control-application I get this error message ...

23:16:33.647 Patchbay deactivated.
23:16:33.663 Statistics reset.
23:16:33.669 JACK is starting...
23:16:33.670 jackd -S -p1024 -dportaudio -d"ASIO::Traktor Audio 2" -r44100 -p1024
23:16:33.693 JACK was started with PID=55139248.
23:16:34.018 JACK has crashed.
23:16:35.924 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.

... and this pop-up window:

I re-installed and re-configured everything several times with different settings, but it simply doesn't work. I'm at a loss.

What are some possible solutions?