Help Please! Cant seem to understand error

 import UIKit

class ViewController: UIViewController {

    enum Error: Error { // error in this line
        case noName
    }

    @IBOutlet weak var nameTextField: UIButton!


    override func viewDidLoad() {
        super.viewDidLoad()
        // 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.
    }

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "startAdventure" {
            if let PageController = segue.destination as? PageController {
                PageController.page = Adventure.story(name: "Farhan")
            }
        }
    }

}