Swiftで画面遷移ができずシミュレータが落ちてしまう

Buttonを押したら画面遷移せずに落ちてしまい下記のようなエラーが出てしまいます。

Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<MyApp9_0.TestViewController 0x7fca49552910> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key sampleText.'
中略
terminating with uncaught exception of type NSException

エラーの内容を調べてもsegueやOutletの接続の問題と書いてありますが、何回確認してもやり直しても接続できています。
下記の接続方法で試しましたが、やはり落ちてしまいます。他に見るべき点があるのでしょうか？
初歩的な問題で申し訳ございませんが、ご指摘いただければ幸いです。
ちなみにButtonを押す画面の前の画面では問題なく画面遷移できます。

①Buttonから画面遷移先へドラッグ＆ドロップ
②画面遷移前のViewControllerでButtonのOutlet及びActionを設定。また、Action内に
self.performSegue(withIdentifier: "画面遷移先のIdentifier", sender: nil)
を入力及びsegueのIdentifierを設定

Swift
1//  TestViewController.swift
2
3import UIKit
4import Firebase
5
6class TestViewController: UIViewController,UITextFieldDelegate {
7        
8    @IBOutlet weak var sampleLabel: UILabel!
9    
10    @IBOutlet weak var inputTextField: UITextField!
11    
12    @IBOutlet weak var sendButton: UIButton!
13    
14    var testArray = [Sample]()
15    
16    let screenSize = UIScreen.main.bounds.size
17    
18
19        override func viewDidLoad() {
20        super.viewDidLoad()
21            
22            inputTextField.delegate = self
23            
24            NotificationCenter.default.addObserver(self, selector: #selector(TestViewController.keyboardWillShow(_ :)), name: UIResponder.keyboardWillShowNotification, object: nil)
25
26            NotificationCenter.default.addObserver(self, selector: #selector(TestViewController.keyboardWillHide(_ :)), name: UIResponder.keyboardWillHideNotification, object: nil)
27
28    }
29    
30    //キーボードを開く
31    @objc func keyboardWillShow(_ notification:NSNotification){
32
33      let keyboardHeight = ((notification.userInfo![UIResponder.keyboardFrameEndUserInfoKey] as Any) as AnyObject).cgRectValue.height
34
35      inputTextField.frame.origin.y = screenSize.height - keyboardHeight - inputTextField.frame.height
36
37
38    }
39
40    //キーボードを閉じる
41    @objc func keyboardWillHide(_ notification:NSNotification){
42
43      inputTextField.frame.origin.y = screenSize.height - inputTextField.frame.height
44
45      guard let rect = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue,
46        let duration = notification.userInfo?[UIResponder.keyboardAnimationDurationUserInfoKey] as? TimeInterval else{return}
47      UIView.animate(withDuration: duration) {
48
49        
50        let transform = CGAffineTransform(translationX: 0, y: 0)
51
52        self.view.transform = transform
53
54      }
55    }
56    
57    //TextFieldを押した時
58    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
59
60      inputTextField.resignFirstResponder()
61
62    }
63    
64    //TextFieldでEnterを押した時
65    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
66
67      textField.resignFirstResponder()
68      return true
69
70    }
71
72    
73    
74    //sendを押した時にfirebaseへ保存
75    @IBAction func sendAction(_ sender: Any) {
76        
77        inputTextField.endEditing(true)
78        inputTextField.isEnabled = false
79        sendButton.isEnabled = false
80        
81        let testDB = Database.database().reference().child("tests")
82        
83        let inputInfo = ["sender":Auth.auth().currentUser?.email,"sample":sampleLabel.text!,"input":inputTextField.text!]
84        
85        testDB.childByAutoId().setValue(inputInfo) { (error, result) in
86            
87            if error != nil{
88                print(error)
89            }else{
90                print("送信完了しました！")
91                self.inputTextField.isEnabled = true
92                self.sendButton.isEnabled = true
93                self.inputTextField.text = ""
94            }
95            
96        }
97        
98    }
99    
100    //Firebaseから取り出す
101    func fetchTestData(){
102        
103        let fetchDataRef = Database.database().reference().child("tests")
104        
105        fetchDataRef.observe(.childAdded) { (snapShot) in
106            let snapShotData = snapShot.value as AnyObject
107            let input = snapShotData.value(forKey: "input")
108            let sample = snapShotData.value(forKey: "sample")
109            let sender = snapShotData.value(forKey: "sender")
110
111            let samples = Sample()
112            samples.input = input as! String
113            samples.sample = sample as! String
114            samples.sender = sender as! String
115            self.testArray.append(samples)
116            //リロードが必要
117        }
118       
119    }
120    
121//    inputデータのみを取得したい（未完成）
122//    func fetchTestDataInLabel(){
123//
124//        let fetchDataRef = Database.database().reference().child("tests")
125//
126//        fetchDataRef.observe(.childChanged) { (snapShot) in
127//            let snapShotData = snapShot.value as AnyObject
128//            let sample = snapShotData.value(forKey: "sample")
129//        }    
130//    }
131    
132    /*
133    // MARK: - Navigation
134
135    // In a storyboard-based application, you will often want to do a little preparation before navigation
136    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
137        // Get the new view controller using segue.destination.
138        // Pass the selected object to the new view controller.
139    }
140    */
141
142}
143