If you are having problems with Smaart interacting with your Rational Acoustics Smaart I-O, and you are running OS X version 10.11.4 or newer, you are likely experiencing a problem with the recent OS X update.
In the 10.11.4 OS X update, the Smaart I-O is renamed internally to "Smaart I_O", which breaks the communication between the Smaart I-O and Smaart. You can verify this if the device is named "Smaart I_O" in Audio/MIDI Setup.
To resolve the problem, perform the following steps:
- Open up the Smaart I-O Control App
- Click Options -> Options
- Select your Smaart I-O device
- Click "Rename"
- Name the device "Smaart IO"
- Save your changes
- Power cycle the I-O by unplugging it, waiting a few seconds, and plugging it back in
This should resolve any issues you are having with the Smaart I-O due to the OSX update. This change only needs to be performed once and will persist even after closing Smaart.