Your @IBAction which unwind segues can have only UIStoryboardSegue as an argument. Try removing sender: Any? from your @IBAction The below code crashes with EXC_BAD_ACCESS error: @IBAction func unwindToRoot(_ segue: UIStoryboardSegue, sender: Any?) { } I resolved it by removing sender argument from IBAction. The below code worked fine for me @IBAction func unwindToRoot(_ segue: UIStoryboardSegue) { }