Why do I get a warning dialog about an unidentified developer when installing GOOSE on macOS?
The software we provide for macOS Sierra can only be downloaded through our website. The default security settings for a Mac do not allow installing apps that have not been registered in the App Store by an identified developer. To install the GOOSE client, you have to open System Preferences -> Security & Privacy -> General. Here you should see the option to allow installing applications from unknown sources.