I have this same problem. I’m not sure that I understood the solution properly.
I replaced “GameWindow” with “Item” in the “New-Empty” project template, and I get a crash:
file:///Users/mgregory/Documents/build-test-Desktop_Qt_5_4_0_clang_64bit-Debug/test.app/Contents/Resources/qml/Main.qml:15 Cannot assign to non-existent property “activeScene”
The program has unexpectedly finished.