So versuche ich, ein einfaches iAd-Banner in meiner Anwendung einzurichten, aber ich erhalte diese beiden Warnungen in der Ausgabe:

WARNING: More than 10 instances of ADBannerView or ADInterstitialView 
currently exist. This is a misuse of the iAd API, and ad performance will 
suffer as a result. This message is printed only once.

un

<Error>: CGAffineTransformInvert: singular matrix.

Dies ist, was ich verwende, um mein @ zu implementierADBannerView:

var adBannerView = ADBannerView()

func loadAds() {
    adBannerView = ADBannerView(frame: CGRect.zeroRect)
    adBannerView.center = CGPoint(x: adBannerView.center.x, y: view.bounds.size.height - adBannerView.frame.size.height / 2)
    adBannerView.delegate = self
    adBannerView.hidden = true
    view.addSubview(adBannerView)
}

//BannerView did load ad
func bannerViewDidLoadAd(banner: ADBannerView!) {
    adBannerView.hidden = false
}
//BannerView failed to load
func bannerView(banner: ADBannerView!, didFailToReceiveAdWithError error: NSError!) {
    adBannerView.hidden = true
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    loadAds()
    //(rest of the code is from here onwards)

Ich habe versucht, dies hinzuzufügen, um den ersten Fehler zu stoppen: (hat nicht funktioniert)

//BannerView will disappear
override func viewWillDisappear(animated: Bool) {
    adBannerView.removeFromSuperview()
    adBannerView.delegate = nil
}