SKAudioNode() crashes when plugging in/out headphones

Question

I am using a SKAudioNode() to play background music in my game. I have a play/pause function and everything is working fine until I plug in my headphones. There is no sound at all and when I call the pause/play function I get this error

AVAudioPlayerNode.mm:333: Start: required condition is false: _engine->IsRunning() com.apple.coreaudio.avfaudio', reason: 'required condition is false: _engine->IsRunning()

Does anyone knows what this means?

Code:

import SpriteKit

class GameScene: SKScene {

let loop = SKAudioNode(fileNamed: "gameloop.mp3")
let play = SKAction.play()
let pause = SKAction.pause()
var isPlaying = Bool()

override func didMoveToView(view: SKView) {  
    loop.runAction(play)
    isPlaying = true
    self.addChild(loop)
}

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
    _ = touches.first as UITouch!

    for _ in touches {
        if isPlaying {
            loop.runAction(pause)
            isPlaying = false
        } else {
            loop.runAction(play)
            isPlaying = true
        } 
    }
}
}

Answer 1

I was not able fix it, but by using AVAudioPlayer() I found a good workaround. Thank you all for supporting me!

import SpriteKit
import AVFoundation

class GameScene: SKScene {    
    var audioPlayer = AVAudioPlayer()  

    override func didMoveToView(view: SKView) {        
        initAudioPlayer("gameloop.mp3")        
    }

    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {        
        _ = touches.first as UITouch!
        for _ in touches {
            toggleBackgroundMusic()            
        }        
    }

    func initAudioPlayer(filename: String) {        
        let url = NSBundle.mainBundle().URLForResource(filename, withExtension: nil)
        guard let newURL = url else {
            print("Could not find file: \(filename)")
            return
        }
        do {
            audioPlayer = try AVAudioPlayer(contentsOfURL: newURL)
            audioPlayer.numberOfLoops = -1
            audioPlayer.prepareToPlay()
            audioPlayer.play()
        } catch let error as NSError {
            print(error.description)
        }        
    }

    func toggleBackgroundMusic() {        
        if audioPlayer.playing {
            audioPlayer.pause()
        } else {
            audioPlayer.play()
        }        
    }    
}