Swift 4 ,must be used from main thread only warning
You’re making this call on a background queue. To fix, try something like… public var context: NSManagedObjectContext DispatchQueue.main.async { var appDelegate = UIApplication.shared.delegate as! AppDelegate context = appDelegate.persistentContainer.viewContext } Although this is a pretty bad way to do this… you’re using your App Delegate as a global variable (which we all know is bad!) You should … Read more