Thread 1: EXC_BREAKPOINT (code=1, subcode=0x18855e560) Error

I was making the cancel button of the memo screen in my iOS memo application. But, when I clicked the cancel button, Thread 1: EXC_BREAKPOINT (code=1, subcode=0x18855e560) error appeared. I used dismiss(animate: true, completion: nil) code

ComposeViewController Code

import UIKit

class ComposeViewController: UIViewController {
    @IBAction func close(_ sender: Any) {
        dismiss(animated: true, completion: nil). //this code was problem
    }
    
    
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

        //something more that is comment code '//'
}