Whose view is not in the window hierarchy only in First Launch - swift

Question

I have an Onboarding screen that I'm showing to the new users when they first open the app.
In my appDelegate I check whether is the first launch or not.
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
// Override point for customization after application launch.
window = UIWindow(frame: UIScreen.main.bounds)
let storyboard = UIStoryboard(name: "Main", bundle: nil)
var initialViewController = storyboard.instantiateViewController(withIdentifier: "OnBoarding")
let userDefaults = UserDefaults.standard
if userDefaults.bool(forKey: "onBoardingComplete") {
initialViewController = storyboard.instantiateViewController(withIdentifier: "MainApp")
}
window?.rootViewController = initialViewController
window?.makeKeyAndVisible()
}
Also I have a collectionViewCell that I have some buttons and when I click them I get an Alert with informations.
Example of one button
#IBAction func guide3Btn(_ sender: Any) {
let infoVC = infoService.info(title: "Title", body: "Information")
self.window?.rootViewController?.present(infoVC, animated: true, completion: nil)
}
When the user first launches the app if he clicks the info button gets this:
Warning: Attempt to present <MyApp.InfoViewController: 0x7f91db45cfb0> on <MyApp.OnbBoardViewController: 0x7f91db506af0> whose view is not in the window hierarchy!
If the user reopens the app everything is ok. I know that when we have first launch we have onBoarding as root controller but I can't understand how to fix this.
Update
This is the infoService class. I use a new storyboard to create the alert.
class InfoService {
func info(title: String, body: String) -> InfoViewController {
let storyboard = UIStoryboard(name: "InfoStoryboard", bundle: .main)
let infoVC = storyboard.instantiateViewController(withIdentifier: "InfoVC") as! InfoViewController
infoVC.infoBody = body
infoVC.infoTitle = title
return infoVC
}
}

Answer 1

You can try add your storyboard instantiate code blocks to main thread using DispatchQueue.main.async like below:
I solved almost all of my whose view is not in the window hierarchy! problems.
DispatchQueue.main.async {
let infoVC = storyboard.instantiateViewController(withIdentifier: "InfoVC") as! InfoViewController
infoVC.infoBody = body
infoVC.infoTitle = title
}
return infoVC
Referenced from : https://stackoverflow.com/a/45126338/4442254