AppConnect Error : AppConnect cannot be instantiated directly

I am trying to Access the MDM using AppConnect SDK in swift 1.2 but it is giving following error :

[AppConnect:Error] AppConnect cannot be instantiated directly. Instead, call +initWithDelegate: and then +sharedInstance.

Code Snippet :

 import UIKit

    @UIApplicationMain
    class AppDelegate: UIResponder, UIApplicationDelegate, AppConnectDelegate {

        var window: UIWindow?        
        var appct = AppConnect()

        func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
            // Override point for customization after application launch.   

            // Initialize the AppConnect library
            AppConnect.initWithDelegate(self)
            self.appct = AppConnect.sharedInstance()
            self.appct.startWithLaunchOptions(launchOptions)

            return true
        } 
}

Application is crashing while accessing the Keys of MobileIron Backend Config file.

Any other way to implement this?

You are initializing AppConnect without delegate

change

var appct = AppConnect();

to

var appct : AppConnect!;