 		super.viewDidLoad()
 		
 		var layer:CALayer = coinView.layer
-		layer.contents = UIImage(named: "coin-heads-medium.png").CGImage
+		layer.contents = UIImage(named: "coin-heads-medium.png")!.CGImage
 	}
 	
 	

					}, completion: {
						_ in
						
						self.coinView.layer.contents = UIImage(named: "coin-heads-medium.png").CGImage
						self.doAnimation()
					})
			})

			}, completion: {
				_ in
				
				self.coinView.layer.contents = UIImage(named: "coin-tails-medium.png")!.CGImage
				UIView.animateWithDuration(self.animationDuration, delay: 0.0, options: UIViewAnimationOptions.CurveLinear, animations: {
					
					var rotation: CATransform3D = self.coinView.layer.transform;
