I’ve been working on a MAX patch which does a number of things to control Reason, and have been developing it on my laptop, which works fine. I copied the files over to my desktop (both OS X), and rewire~ doesn’t appear to be behaving. When I attempt to start the patch, I get "error: ad_rewire: error starting audio. Is ReWire mixer running?"
I whipped up a cheesy "test patch" for this problem, and sure enough, it works on the laptop, but not on the desktop. I checked the midi settings, the appear to be the same. Reason reports it’s running in slave mode.