致命错误：在隐式展开一个可选值时意外发现nil。火箭发射

Question

每次我尝试运行我的应用程序时，都会显示以下错误： 意外发现nil，同时隐式展开一个可选值

能帮我吗？

let path = Bundle.main.path(forResource: "rocketsound", ofType: "wav")!
    let url = URL(fileURLWithPath: path)
    do {
        player = try AVAudioPlayer(contentsOf: url)
        player.prepareToPlay()
    } catch let error as NSError {
        print(error.description)
    }
}
@IBAction func buttonisPressed(_ sender: Any) {

    player.play()

    UIView.animate(withDuration: 2.3, animations: {
        self.rocket.frame = CGRect(x: 0, y: 140, width: 375, height: 402)
    }) { (finished) in
        self.textLbl.ishidden = true
        self.buttonLbl.ishidden = true
    }
}