User Profile

For some reason, when I select an .sks file in the navigator, the editor for the scene doesn't show up. I do see the scene hierarchy, which usually appears on the left in the editor, but the actual scene, showing the sprites, labels, etc., is entirely missing. Is there some setting that causes .sks files to not be shown that I need to change? I've updated to the newest release, and cleared out the Xcode preferences in ~/Library/Application Support/Xcode, but the problem persists.