Shutter Stream locks up on Sierra when the Nikon camera is powered off or disconnected.
With some Mac configurations running Sierra, you will need to make sure that your Nikon camera is connected and powered on before starting Shutter Stream. The Nikon SDK sometimes locks up on certain Sierra machines, when the SDK is searching for the Nikon camera and it cannot find it. Please also see this article about Canon cameras on Sierra. As soon as Nikon provides an updated SDK, resolving this issue, we will integrate it into Shutter Stream.