title: In app purchase Buy product working on 1 view but not the other
body: <p>Ive got an IOS app where In app purchases have been set up. I have 2 different views with the same code. One is being called normally through the storyboard, another is being called as a Modal Segue</p>
  
  <p>The one being called as a Segue CONSISTENTLY crashes on this line of code:</p>
  
  <pre><code> SKProduct *product = [_products objectAtIndex:buyAdButton.tag];
  </code></pre>
  
  <p><strong>in the context of:</strong>    </p>
  
  <pre><code>- (void)buyButtonTapped:(id)sender {
  
      UIButton *buyAdButton = (UIButton *)sender;
      SKProduct *product = [_products objectAtIndex:buyAdButton.tag];
  
      //    NSLog(@"Buying %@...", product.productIdentifier);
      [[RageIAPHelper sharedInstance] buyProduct:product];
  
  }
  </code></pre>
  
  <p>I have no idea why this is happening. The code on both views is IDENTICAL but the only difference I know is that one opens via a Segue and the other doesn't. Could this be strangely causing an issue?</p>
  
  <p>I can provide any other info if it helps</p>