I am trying to detect if the app is being opened for the first time. I've put this piece of code in my ViewController's `viewDidLoad()`

```
override func viewDidLoad() {
        super.viewDidLoad()

        let launchedBefore = UserDefaults.standard.bool(forKey: "launchedBefore")
        if launchedBefore  {
            performSegue(withIdentifier: "toMainController", sender: self)
            print("launchedBefore")
        } else {
            performSegue(withIdentifier: "toTutorialController", sender: self)
            UserDefaults.standard.set(true, forKey: "launchedBefore")
            print("not launchedBefore")

        }
    }

```

But, whenever the ViewController launches, no segues are performed. But thext I told it to print, is printed. If it matters, the view that the segue `"toMainController"` goes to is a `UITabViewController`, and the view that the segue `"toTutorialController"` goes to is just a `UIViewController`.

Does anyone have any ideas why this isn't working?

**UPDATE**

I found this error

> 
> 2017-06-30 09:02:32.984 AppName[29732:24744712] Warning: Attempt to
>  present on <
>  AppName.ViewController: 0x7fcbfa908ed0> whose view is not in the
>  window hierarchy!
> 
> 
>