Segueを用いた画面遷移でエラーになり直し方がわかりません。

前提・実現したいこと

Swift初心者でDiaryを作っています。
Qiitaを用いて勉強しています。

発生している問題・エラーメッセージ

Runしたときに画面遷移が上手くいかないです
Buildの時点ではSucceededが出ます

2018-12-27 20:29:00.802292-0600 DailySampler[4997:520087] Unknown class DiaryViewController in Interface Builder file.
Could not cast value of type 'UIViewController' (0x116c37a10) to 'DailySampler.DiaryViewController' (0x10a8dfc28).
2018-12-27 20:29:00.803868-0600 DailySampler[4997:520087] Could not cast value of type 'UIViewController' (0x116c37a10) to 'DailySampler.DiaryViewController' (0x10a8dfc28).

ViewControllerのソースコード

swift
1
2import UIKit
3import JBDatePicker
4
5class ViewController: UIViewController, JBDatePickerViewDelegate {
6    
7    @IBOutlet var datePicker: JBDatePickerView!
8    @IBOutlet var writeButton: UIButton!
9     var date: String!
10    
11    lazy var dateFormatter: DateFormatter = {
12        var formatter = DateFormatter()
13        formatter.timeStyle = .none
14        formatter.dateStyle = .medium
15        return formatter
16    }()
17    
18    override func viewDidLoad() {
19        super.viewDidLoad()
20        // Do any additional setup after loading the view, typically from a nib.
21        datePicker.delegate = self
22    }
23    
24    func didSelectDay(_ dayView: JBDatePickerDayView) {
25        print("date selected: (dayView.date!)")
26         date = dateFormatter.string(from: dayView.date!)
27    }
28
29    @IBAction func writeButtonPushed(_ sender: UIButton) {
30        self.performSegue(withIdentifier: "toDiary", sender: nil)
31    }
32    
33    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
34        if (segue.identifier == "toDiary") {
35           let diaryView = segue.destination as! DiaryViewController
36//          ⬆︎ココ!
37            diaryView.date = self.date
38        }
39    }
40    
41    override func viewDidLayoutSubviews() {
42        super.viewDidLayoutSubviews()
43        
44        datePicker.updateLayout()
45    }
46    
47}
48

DiaryViewControllerのソースコード

swift
1
2import UIKit
3import RealmSwift
4
5class DiaryViewController: UIViewController {
6    
7    @IBOutlet var dateLabel: UILabel!
8    @IBOutlet var contextTextView: UITableView!
9    
10    var date: String! 
11    
12    override func viewWillAppear(_ animated: Bool) {
13        super.viewWillAppear(animated)
14        
15        dateLabel.text = date
16        
17    }
18    
19    override func viewDidLoad() {
20        super.viewDidLoad()
21   }
22    
23
24    override func didReceiveMemoryWarning() {
25        super.didReceiveMemoryWarning()
26        
27    }
28    
29    @IBAction func savebuttonpushed(_sender: UIButton) {
30    }
31    /*
32    // MARK: - Navigation
33
34    // In a storyboard-based application, you will often want to do a little preparation before navigation
35    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
36        // Get the new view controller using segue.destination.
37        // Pass the selected object to the new view controller.
38    }
39    */
40
41}
42

Diaryのソースコード

swift
1import Foundation
2import RealmSwift
3
4class diary: Object {
5    @objc dynamic var date = "" 
6    @objc dynamic var context = "" 
7    @objc dynamic var photo: NSData? = nil 
8    
9    override static func primaryKey() -> String? {
10        return "date"
11    }
12    
13}