Xcode – Swift Unrecognised Selector Send to Instance

I’m a complete newbie and started learning Swift through an online course last week.

My problem is, that I somehow receive the same error in different projects. Every time I run the Simulator and click on one of my linked buttons, nothing happens and the Xcode gives me the following error message: "unrecognized selector send to instance". Can someone help me? 🙂

I followed the course very closely and got the same code as the person in video, also I started from scratch and neither did work.

class ViewController: UIViewController {
    
    let eggTimes = ["Soft": 300, "Medium": 420, "Hard": 720]
    
    var secondsRemaining = 60
       
    @IBAction func hardnessSelected(_ sender: UIButton) {
        let hardness = sender.currentTitle!

        secondsRemaining = eggTimes[hardness]!
        
        Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(updateTimer), userInfo: nil, repeats: true)           
    }
    
    @objc func updateTimer() {
        if secondsRemaining > 0 {
            print("(secondsRemaining) seconds.")
            secondsRemaining -= 1
        }
    }
}