I'm getting an error while trying to run the FunFact on my iPhone 6

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var funFactLabel: UILabel!


    let factModel = FactModel()

    @IBOutlet weak var funFactButton: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()
        funFactLabel.text = factModel.getRandomFact()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func showFunFact() {
        let randomColor = ColorModel().getRandomColor()
        view.backgroundColor = randomColor
        funFactButton.tintColor = randomColor

        funFactLabel.text = factModel.getRandomFact()
    }
}