Hi! I am super new to Xcode and I was trying to write my first project. I created two UIViewControllers and a button in the first ViewController which will bring me to the second ViewController when pressed. Here is the code import UIKit class ViewController: UIViewController {     override func viewDidLoad() {         super.viewDidLoad()         // Do any additional setup after loading the view.     }     @IBAction func buttonPressed(_ sender: UIButton) {         performSegue(withIdentifier: "goToSecond", sender: nil)     } } However, I kept getting this error from the AppDelegate at the @main line: Thread 1: "-[UIViewController buttonPressed:]: unrecognized selector sent to instance 0x12df0a110" import UIKit @main class AppDelegate: UIResponder, UIApplicationDelegate {     func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {         // Override point for customization after application launch.         return true     }     // MARK: UISceneSession Lifecycle     func application(_ application: UIApplication, configurationForConnecting connectingSceneSession: UISceneSession, options: UIScene.ConnectionOptions) -> UISceneConfiguration {         // Called when a new scene session is being created.         // Use this method to select a configuration to create the new scene with.         return UISceneConfiguration(name: "Default Configuration", sessionRole: connectingSceneSession.role)     }     func application(_ application: UIApplication, didDiscardSceneSessions sceneSessions: Set<UISceneSession>) {         // Called when the user discards a scene session.         // If any sessions were discarded while the application was not running, this will be called shortly after application:didFinishLaunchingWithOptions.         // Use this method to release any resources that were specific to the discarded scenes, as they will not return.     } } If I changed @main to @UIApplicationMain, the same error will instead appear at the class AppDelegate: UIResponder, UIApplicationDelegate { line. I also tried to remove and recreate the connection, but still no luck. Any suggestions?