iPhone app says "This Devialet is busy"

[Hifi_swlon]

Greetings,

I had AIR working (intermittently) when I first set up the D200, but gave up on it a long time ago and have been happily using a Mac Mini via USB to the D200 together with ROON.  However, I thought I'd give it another try since I thought it would be nice to stream from my phone occasionally.  I select My Music from the Devialet App, but get this error:

"Another device is controlling the Devialet. Please stop playback on this other device and try again."

I don't have AIR running on any computer, so I'm not sure what it thinks is controlling the device.

Anyone have an idea what ti could be?

Thanks,
  Norm

I wasn't even aware you could stream to the Experts via an iPhone App. Which App is it?