iOS Debugging

I ran into a problem when auto-converting to Swift 3.0. The "result of call is unused" warning pops up after converting to Swift 3.0 (previously all worked and the images displayed normally). Just silencing the error with "@discardableResult" or "_ =" doesn't work. The problem is the following: The complete obstacles are displayed in the game normally, but when the character crashes into them, they get destroyed and the crashed object image should appear. But it doesn't. Somehow the code lost the connection with this image when it updated the code to Swift 3.0 standards. Instead a big red X image appears in the place where the destroyed obstacle should be displayed. The thing is that whatever I do, the object in the game isn’t showing as it should. Like I said, previously it worked, but now it doesn’t anymore. When the character runs into the object and it crashes it, the game should display a crashed object, but instead it shows an image with a red “X” as if the image isn’t there.