Google Admob广告运行时例外

Question

当我打电话

[GADRequest request];

我收到运行时异常

由于未捕获的异常'NSInvalidArgumentException'而终止应用程序，原因：' - [GADTimingManager initWithIdentifier：]。

相同的代码在示例中工作正常。我不知道他们可能会发生这种情况

在ViewDidLoad中，我有以下声明

    self.bannerView = [[[GADBannerView alloc] initWithFrame: CGRectMake(0.0, 5.0, 320.0, 50.0)] autorelease];
    self.bannerView.adUnitID = AdMobDefaultiPhonePublisherId;
    self.bannerView.delegate = self;
    [self.bannerView setRootViewController:self];
    [self.view addSubview:self.bannerView];

     [self.bannerView loadRequest:[self createRequest]];

然后我有以下方法

- (GADRequest *)createRequest {
    GADRequest *request = [GADRequest request];

      return request;
}

和

- (void) adViewDidReceiveAd:(GADBannerView *)view {

}

- (void)adView:(GADBannerView *)view
didFailToReceiveAdWithError:(GADRequestError *)error {
    NSLog(@"Failed to receive ad with error: %@", [error localizedFailureReason]);
}