I notice that El Capitan disallows direct running of Shake, but it runs fine when you open the package and directly run the binary (and multiple instances).
/Applications/Shake/shake.app/Contents/MacOS/shake
The only warning I'm seeing is "This application, or a library it uses, is using the deprecated Carbon Component Manager for hosting Audio Units. Support for this will be removed in a future release. Also, this makes the host incompatible with version 3 audio units. Please transition to the API's in AudioComponent.h.".
