xcode8 エラー表示

現在音楽記憶力ゲームを作成中です。

画像１の再生ボタンを押すと、青・赤・緑・ピンクがそれぞれ１つずつ点滅しながら音が流れ、流れた順番を記憶しその手順通りになぞるというゲームです。

ですが。。。下記の写真の内容のエラーが出てしまい色々調べたのですが、わかりません。

シュミレーションで確認をし、ボタンをクリックするとそれぞれ音が流れるところまではできたのですが、その後からの再生ボタンクリック→ゲームスタート→ランダムに点滅＋音が流れる→それを記憶→同じ順番にクリックといった工程が行えません。（※シュミレーション再生を押すと写真のようなエラーが出て再生できません。）

よければ誰か教えてくださいm(_ _)m

（※エラーは下記の写真（２〜３）の２箇所です）

１

２

３

![]

import
1import SpriteKit
2import GameplayKit
3import AVFoundation
4
5
6class GameViewController: UIViewController,AVAudioPlayerDelegate {
7    @IBOutlet weak var startGameButton: UIButton!
8    
9    @IBOutlet var soundButton: [UIButton]!
10    
11    @IBOutlet weak var levelLabel: UILabel!
12
13    var sound1Player:AVAudioPlayer!
14    var sound2Player:AVAudioPlayer!
15    var sound3Player:AVAudioPlayer!
16    var sound4Player:AVAudioPlayer!
17    var PlayList = [Int]()
18    var currenItem = 0
19    var numberOfTaps = 0
20    var readyForUser = false
21    var level = 1
22
23    override func viewDidLoad() {
24        super.viewDidLoad()
25        setupAudioFiles()
26    }
27    
28    func setupAudioFiles(){
29        
30        let soundFilePath = Bundle.main.path(forResource:"1", ofType: "wav")
31        let soundFileURL = URL(fileURLWithPath: soundFilePath!)
32        let soundFilePath2 = Bundle.main.path(forResource:"2", ofType: "wav")
33        let soundFileURL2 = URL(fileURLWithPath: soundFilePath2!)
34        let soundFilePath3 = Bundle.main.path(forResource:"3", ofType: "wav")
35        let soundFileURL3 = URL(fileURLWithPath: soundFilePath3!)
36        let soundFilePath4 = Bundle.main.path(forResource:"4", ofType: "wav")
37        let soundFileURL4 = URL(fileURLWithPath: soundFilePath4!)
38        do{
39            sound1Player = try AVAudioPlayer(contentsOf: soundFileURL)
40            sound2Player = try AVAudioPlayer(contentsOf: soundFileURL2)
41            sound3Player = try AVAudioPlayer(contentsOf: soundFileURL3)
42            sound4Player = try AVAudioPlayer(contentsOf: soundFileURL4)
43            
44        } catch {
45            print(error)
46            
47        }
48        
49        sound1Player.delegate = self
50        sound2Player.delegate = self
51        sound3Player.delegate = self
52        sound4Player.delegate = self
53        
54        sound1Player.numberOfLoops = 0
55        sound2Player.numberOfLoops = 0
56        sound3Player.numberOfLoops = 0
57        sound4Player.numberOfLoops = 0
58
59    }
60    
61    @IBAction func soundButtonPressed(_ sender: AnyObject) {
62        
63        if readyForUser {
64        
65        let button = sender as! UIButton
66        
67        switch button.tag {
68        case 1:
69            sound1Player.play()
70            checkIfCorrect(buttonPressed: 1)
71        case 2:
72            sound2Player.play()
73            checkIfCorrect(buttonPressed: 2)
74
75        case 3:
76            sound3Player.play()
77            checkIfCorrect(buttonPressed: 3)
78
79        case 4:
80            sound4Player.play()
81            checkIfCorrect(buttonPressed: 4)
82
83            
84            break
85        default:
86            break
87        }
88        
89        }
90
91
92    }
93
94    func checkIfCorrect (buttonPressed:Int){
95     
96        if buttonPressed == PlayList[numberOfTaps] {
97        
98        if numberOfTaps == PlayList.count - 1 { //we have arrived at the last item of the playList
99    
100        let time = DispatchTime.now(dispatch_time_t(DISPATCH_TIME_NOW),Int64(NSEC_PER_SEC))
101            
102        dispatch_after(time, DispatchQueue.main, {
103
104        
105        self.nextRound()
106        
107            })
108            
109            return
110        
111            }
112            
113            numberOfTaps += 1
114            
115            
116        }else{//GAME OVER
117
118            resetGame()
119            
120        }
121    }
122
123            func resetGame() {
124                
125                level = 1
126                readyForUser = false
127                numberOfTaps = 0
128                currenItem = 0
129                PlayList = []
130                levelLabel.text = "GAME OVER"
131                startGameButton.isHidden = false
132                disableButtons()
133    }
134    
135            
136        func nextRound() {
137            
138        level += 1
139        levelLabel.text = "level\(level)"
140        readyForUser = false
141        
142        numberOfTaps = 0
143        currenItem = 0
144        disableButtons()
145            
146            
147        let randomNumber = Int(arc4random_uniform(4) + 1)
148        
149        PlayList.append(randomNumber)
150        
151        playNextItem()
152            
153            }
154
155
156    @IBAction func startGame(_ sender: AnyObject) {
157        disableButtons()
158        levelLabel.text = "Lebel 1"
159
160        
161        
162        let randomNunber = Int(arc4random_uniform(4) + 1)
163        PlayList.append(randomNunber)
164        startGameButton.isHidden = true
165        playNextItem()
166        disableButtons()
167        
168    }
169
170        
171        func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer, successfully flag: Bool) {
172            
173            if currenItem <= PlayList.count - 1{
174               playNextItem()
175                
176            }else{
177                readyForUser = true
178                
179  
180            }
181    
182        }
183        
184        func playNextItem(){
185        let selectedItem = PlayList[currenItem]
186         
187            switch selectedItem {
188   
189            case 1:
190                highlightButtonWithTag (tag: 1)
191                sound1Player.play()
192                break
193
194            case 2:
195               highlightButtonWithTag (tag: 2)
196                sound2Player.play()
197                break
198  
199            case 3:
200                highlightButtonWithTag (tag: 3)
201                sound3Player.play()
202                break
203      
204            case 4:
205               highlightButtonWithTag (tag: 4)
206                sound4Player.play()
207                break
208        
209            default:
210                break;
211       
212            }
213    
214        
215        currenItem += 1
216        
217        
218        }
219        
220        func highlightButtonWithTag (tag:Int){
221            switch tag {
222            case 1:
223                
224                soundButton[tag - 1].setImage(UIImage(named:"redPressed"), for: .normal)
225            case 2:
226                
227                soundButton[tag - 1].setImage(UIImage(named:"redPressed"), for: .normal)
228            case 3:
229                
230                soundButton[tag - 1].setImage(UIImage(named:"redPressed"), for: .normal)
231            case 4:
232                
233                soundButton[tag - 1].setImage(UIImage(named:"redPressed"), for: .normal)
234            default:
235                break
236   
237            }
238  
239        }
240         func resetButtonHightlights() {
241
242            soundButton[1].setImage(UIImage(named:"blue"),for: .normal)
243            soundButton[2].setImage(UIImage(named:"green"),for: .normal)
244            soundButton[3].setImage(UIImage(named:"red"),for: .normal)
245            soundButton[4].setImage(UIImage(named:"purple"),for: .normal)
246   
247        }
248
249        func resetButtonHightlights() {
250    
251            soundButton[1].setImage(UIImage(named:"bluePressed"),for: .normal)
252            soundButton[2].setImage(UIImage(named:"greenPressed"),for: .normal)
253            soundButton[3].setImage(UIImage(named:"redPressed"),for: .normal)
254            soundButton[4].setImage(UIImage(named:"pueplePressed"),for: .normal)
255
256        }
257
258 func disableButtons () {
259        for button in soundButton {
260            button.isUserInteractionEnabled = false
261
262}
263
264 func enableButtons() {
265        for button in soundButton {
266            button.isUserInteractionEnabled = true
267   
268    }
269
270   func didReceiveMemoryWarning(){
271            super.didReceiveMemoryWarning()
272            // Release any cached data, images, etc that aren't in use.
273