Error “Thread 1: signal SIGABRT” when switching to another viewController by pressing a button - swift

Error "Thread 1: signal SIGABRT" when switching to the second viewController (class "Type1ViewController"), I tried to fix everything, here is the code from ViewController.swift and the screen Main.storyboard: Classes view-shek checked match. The error also occurs in the absence of all TextFields on the second screen. The error is displayed here in AppDelegate:

 import UIKit var position: Int = 1 var positionSecondBack: Int = 0 var answer: String = "" //======================================================================= //------------------------ first view controller ------------------------ //======================================================================= class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate { @IBOutlet weak var LabelTypeEc: UILabel! @IBOutlet weak var LabelType: UILabel! @IBOutlet weak var Button1: UIButton! @IBOutlet weak var Button2: UIButton! @IBOutlet weak var Button3: UIButton! @IBOutlet weak var Next1Butt: UIButton! @IBOutlet weak var ProblemTypePicker: UIPickerView! @IBOutlet weak var PickerAP: UIPickerView! @IBOutlet weak var PickerDP: UIPickerView! @IBOutlet weak var PickerV: UIPickerView! override func viewDidLoad() { super.viewDidLoad() ProblemTypePicker.layer.cornerRadius = 15 PickerAP.layer.cornerRadius = 15 PickerDP.layer.cornerRadius = 15 PickerV.layer.cornerRadius = 15 LabelTypeEc.layer.cornerRadius = 5 LabelType.layer.cornerRadius = 5 Button1.layer.cornerRadius = 15 Button2.layer.cornerRadius = 15 Button3.layer.cornerRadius = 15 Next1Butt.layer.cornerRadius = 15 Button1.setTitle(" Вопросы ", for: .normal) Button2.setTitle(" Вопросы ", for: .normal) Button3.setTitle(" Вопросы ", for: .normal) ProblemTypePicker.delegate = self ProblemTypePicker.dataSource = self PickerAP.delegate = self PickerAP.dataSource = self PickerDP.delegate = self PickerDP.dataSource = self PickerV.delegate = self PickerV.dataSource = self } var list1 = ["аннуитентные платежи", "дифференцированые платежи", "вклады"] var list2 = ["1-ый тип", "2-ый тип", "3-ый тип"] var list3 = ["4-ый тип", "5-ый тип", "6-ый тип"] var list4 = ["7-ый тип", "8-ый тип", "-"] //how much stacks in pickerView func numberOfComponents(in pickerView: UIPickerView) -> Int { return 1 } func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int { var countrows : Int = list1.count if pickerView == ProblemTypePicker { countrows = self.list2.count } return countrows } func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? { if pickerView == ProblemTypePicker { let titleRow = list1[row] return titleRow } else if pickerView == PickerAP { let titleRow = list2[row] return titleRow } else if pickerView == PickerDP { let titleRow = list3[row] return titleRow } else if pickerView == PickerV { let titleRow = list4[row] return titleRow } return "" } func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) { if pickerView == ProblemTypePicker { //buttons witch allow us go to "Type docs" //and //PickerViews what contain from "1 Type" to "9 Type" if row == 0 { position = 1 PickerAP.isHidden = false PickerDP.isHidden = true PickerV.isHidden = true Button1.isHidden = false Button2.isHidden = true Button3.isHidden = true } else if row == 1 { position = 4 PickerAP.isHidden = true PickerDP.isHidden = false PickerV.isHidden = true Button2.isHidden = false Button1.isHidden = true Button3.isHidden = true } else if row == 2 { position = 7 PickerAP.isHidden = true PickerDP.isHidden = true PickerV.isHidden = false Button3.isHidden = false Button2.isHidden = true Button1.isHidden = true } } //what type of problem if pickerView == PickerAP { if row == 0 { position = 1 } else if row == 1 { position = 2 } else if row == 2 { position = 3 } } if pickerView == PickerDP { if row == 0 { position = 4 } else if row == 1 { position = 5 } else if row == 2 { position = 6 } } if pickerView == PickerV { if row == 0 { position = 7 } else if row == 1 || row == 2 { position = 8 } } if position == 1 { Next1Butt.isHidden = false } else if position == 2 { Next1Butt.isHidden = true } else if position == 3 { Next1Butt.isHidden = true } else if position == 4 { Next1Butt.isHidden = true } else if position == 5 { Next1Butt.isHidden = true } else if position == 6 { Next1Butt.isHidden = true } else if position == 7 { Next1Butt.isHidden = true } else if position == 8 { Next1Butt.isHidden = true } else if position == 9 { } } } //======================================================================= //---------------------- 1 Type1ViewController 1 ------------------------ //======================================================================= class Type1ViewController: UIViewController { @IBOutlet weak var LabelType: UILabel! @IBOutlet weak var ButtonBack: UIButton! @IBOutlet weak var ButtonNext: UIButton! @IBOutlet weak var Label1: UILabel! @IBOutlet weak var Label2: UILabel! @IBOutlet weak var Label3: UILabel! @IBOutlet weak var Lanel4: UILabel! //textFields @IBOutlet weak var TextField_1Type_1: UITextField! @IBOutlet weak var TextField_2Type_1: UITextField! @IBOutlet weak var TextField_3Type_1: UITextField! @IBOutlet weak var TextField_4Type_1: UITextField! override func viewDidLoad() { super.viewDidLoad() ButtonBack.layer.cornerRadius = 15 ButtonNext.layer.cornerRadius = 15 } }