2011 Mac machines use first-generation Thunderbolt™ ports. Occasionally, these may reject connections with our devices (and others).
If you experience this issue, please try the following steps:
Remove the driver.
Disconnect the Thunderbolt™ cable from the computer.
Power off the computer.
Start the computer and plug the Thunderbolt™ cable back in.
Reinstall the driver.
After installing the driver, do not disconnect the device or restart the computer.
Check if the device appears in Audio MIDI Setup and the Control Panel.
This workaround has resolved the issue for some of our users.
Please note: Using USB is preferred on 2011 Macs due to stability issues with the first revision of Apple Thunderbolt ports.