Ableton Live doesn't load the Jack Router

I’m on a MacPro running 10.5.8, Live 8.1.1 and the 0.85 version of Jack.

When I try to select the Jack Router as an audio device I get a “failed to open the audio device “Jack Router””-message.

Mixbus runs fine by itself but my wish is to stream audio from Live to Mixbus.

Any ideas on how to solve this?

IN Live:
Try and select Core audio driver, and jack router input/output device.
Select ext. output and select channel

In Mixbus:

Click on the input, select edit. There you will find the output you selected in Live. Hit record.