线程1:信号SIGABRT,黑屏,“无法加载捆绑包中的NIB”[重复]

当我启动模拟器时,一个黑屏出现了!与AppDelegate中的错误“线程1:信号SIGABRT”相同。最后,右角的一个错误告诉我,他们无法在捆绑包中加载NIB。我对编码也很陌生,所以我还有很多东西要学。如果你喜欢,你可以给我一些提示。如果您需要查看,以下是我的代码:

import UIKit

class ViewController: UIViewController {
    public var screenWidth: CGFloat {
        return UIScreen.main.bounds.width/100
    }
    var thereIsInternet:Bool?
    var reachability:Reachability?
    var numberTowardCompletion = 0
    override func viewDidLoad() {
        super.viewDidLoad()
        barProgress.frame.size.width = 0
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
        barProgress.frame.size.width = 0
        self.reachability = Reachability.init()
        if ((self.reachability!.connection) != .none) {
            thereIsInternet = true
        } else {
            thereIsInternet = false
        }
        let when = DispatchTime.now() + 5
        DispatchQueue.main.asyncAfter(deadline: when) {

        }
    }


    @IBOutlet weak var barProgress: UIView!
    @IBOutlet var percent: UILabel!
    @IBOutlet var loading: UILabel!

    func checkingInternet() {
        if thereIsInternet == true {
            loading.text = "Internet is present"
            barProgress.frame.size.width = screenWidth * CGFloat(15)
        } else {
            loading.text = "ERROR"
            let alert = UIAlertController(title: "Connection Problem", message: "Make sure you're connected to the internet", preferredStyle: .alert)
            let restartAction = UIAlertAction(title: "Restart", style: .default, handler: { (UIAlertAction) in
                self.startOver()
            })
            alert.addAction(restartAction)
            present(alert, animated: true, completion: nil)
        }
    }
    func startOver() {
        barProgress.frame.size.width = 0
        self.reachability = Reachability.init()
        if ((self.reachability!.connection) != .none) {
            thereIsInternet = true
        } else {
            thereIsInternet = false
        }
        let when = DispatchTime.now() + 5 // change 2 to desired number of seconds
        DispatchQueue.main.asyncAfter(deadline: when) {

        }
        checkingInternet()
    }
}