Recently I started to learn swift from Apple app design workbook. There is a simple exercise, you should display an interactive map, but I encountered an error, which I cannot google anywhere. After starting the code Playground displays an error "The live view is not visible due to having zero width and zero height". There are only 3 lines of code. Any one have any idea what is going wrong, or what I can do? import PlaygroundSupport import MapKit PlaygroundPage.current.liveView = MKMapView()