Xcode 12.4 and simulator : black screen on 2018 Mac Mini

I'm runnning Xcode 12.4 & am using Core Data and when I launch a device simulator they only show a black screen.


ApDelegate.swift


import UIKit
import CoreData
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
internal func application( application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
return true
}



  func applicationWillTerminate( application: UIApplication) {
self.saveContext()
}

// MARK: UISceneSession Lifecycle
func application( application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {

    return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)
}

func application( application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {
}
// MARK: - Core Data stack

lazy var persistentContainer: NSPersistentContainer = {
let container = NSPersistentContainer(name: "DataModel")
container.loadPersistentStores(completionHandler: { (storeDescription, error) in

            if let error = error as NSError? {
fatalError("Unresolved error \(error), \(error.userInfo)")
}
})
return container
}()



    // MARK: - Core Data Saving support

func saveContext () {
let context = persistentContainer.viewContext
if context.hasChanges {
do {
try context.save()
} catch {
let nserror = error as NSError
fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
}
}
}
}



ViewController



import UIKit
import CoreData

class TodoListViewController: UITableViewController {

     var itemArray = [Item]()
let dataFilePath = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first?.appendingPathComponent("Items.plist")

    let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext

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

// MARK: - Tableview Datasource Methods

override func tableView( tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return itemArray.count
}

override func tableView( tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "ToDoItemCell", for: indexPath)
let item = itemArray[indexPath.row]
cell.textLabel?.text = item.title
// Ternary Operater ==>
cell.accessoryType = item.done ? .checkmark : .none
return cell
}

// MARK: - Tableview Delegate Methods
override func tableView( tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
itemArray[indexPath.row].done = !itemArray[indexPath.row].done
saveItems()
tableView.reloadData()
tableView.deselectRow(at: indexPath, animated: true)
}

//MARK: - Add New Items

    @IBAction func addButtonPressed( sender: UIBarButtonItem) {
var textField = UITextField()
let alert = UIAlertController(title: "Add New Todoey Item", message: "", preferredStyle: .alert)
  let action = UIAlertAction(title: "Add Item", style: .default) { (action) in
let newItem = Item(context: self.context)
newItem.title = textField.text!
newItem.done = false
self.itemArray.append(newItem)
self.saveItems()
self.tableView.reloadData()
}
alert.addTextField { (alertTextField) in
alertTextField.placeholder = "Create new item"
textField = alertTextField
}
alert.addAction(action)
present(alert, animated: true, completion: nil)
}

//MARK: - Model Manupulation Methods
func saveItems(){

            do {

                try context.save()

            } catch {

                 print("Error while saving the context \(error)")

            }

    }

    

    

//    func loadItems() {

//        if let data = try? Data(contentsOf: dataFilePath!) {

//            let decoder = PropertyListDecoder()

//            do {

//                itemArray = try decoder.decode([Item].self, from: data)

//            } catch {

//                print("Error decoding Item Array \(error)")

//            }

//        }

//

//    }

}