XCode中的Swift EXC_BAD_INSTRUCTION错误

Question

在我的Xcode Swift应用程序中，我收到了错误

EXC_BAD_INSTRUCTION(code=EXC_1386_INVOP, subcode=0x0) 

在skView.presentScene(scene) GameViewController方法

中的viewDidLoad行

import UIKit
import SpriteKit

extension SKNode {
    class func unarchiveFromFile(file : NSString) -> SKNode? {
        if let path = NSBundle.mainBundle().pathForResource(file as String, ofType: "sks") {
            var sceneData = NSData(contentsOfFile: path, options: .DataReadingMappedIfSafe, error: nil)!
            var archiver = NSKeyedUnarchiver(forReadingWithData: sceneData)

            archiver.setClass(self.classForKeyedUnarchiver(), forClassName: "SKScene")
            let scene = archiver.decodeObjectForKey(NSKeyedArchiveRootObjectKey) as! GameScene
            archiver.finishDecoding()
            return scene
        } else {
            return nil
        }
    }
}

class GameViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        if let scene = GameScene.unarchiveFromFile("GameScene") as? GameScene {
            // Configure the view.
            let skView = self.view as! SKView
            skView.showsFPS = true
            skView.showsNodeCount = true

            /* Sprite Kit applies additional optimizations to improve rendering performance */
            skView.ignoresSiblingOrder = true

            /* Set the scale mode to scale to fit the window */
            scene.scaleMode = .AspectFill

            skView.presentScene(scene) // This is the offending line
        }
    }

    override func shouldAutorotate() -> Bool {
        return true
    }

    override func supportedInterfaceOrientations() -> Int {
        if UIDevice.currentDevice().userInterfaceIdiom == .Phone {
            return Int(UIInterfaceOrientationMask.AllButUpsideDown.rawValue)
        } else {
            return Int(UIInterfaceOrientationMask.All.rawValue)
        }
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Release any cached data, images, etc that aren't in use.
    }

    override func prefersStatusBarHidden() -> Bool {
        return true
    }
}