I am getting ERROR ITMS-90497, Invalid Image Asset -Top Shelf Image - must be opaque, when using this image:
I'm just testing with this image to get it working and trying to submit a tvOS application to TestFlight.
The PNG image you're using contains Alpha Channels. Open the image with Preview and go to File>Export>Uncheck Alpha>Save. This will save the image without Alpha Channels.
来源：https://stackoverflow.com/questions/32834660/invalid-image-asset-top-shelf-image-must-be-opaque