title: In-App Purchase: Invalid Product Identifier iOS 9 Swift 2
body: <p>I keep getting this invalid product identifiers. Is my code fine? what could be the problem? Ive written the code to print out my in app purchases but it keeps going to this if statement:</p>
  
  <pre><code>if response.invalidProductIdentifiers.count != 0 {
          print(response)
          print(response.invalidProductIdentifiers.description)
      }
  </code></pre>
  
  <p>In my in-app purchase page on Itunes connect I have the exact ID for the product copied into xcode yet it still does not work.</p>
  
  <p>My full code:</p>
  
  <pre><code>//global variables
  var productsArray: Array&lt;SKProduct!&gt; = []
  var productIdentifiers = Set&lt;NSObject&gt;()
  
  func requestProductInfo() {
      if SKPaymentQueue.canMakePayments() {
          //let productIdentifiers = NSSet(array: productIDs)
          let productRequest = SKProductsRequest(productIdentifiers: self.productIdentifiers as! Set&lt;String&gt;)
  
          productRequest.delegate = self
          productRequest.start()
      }
      else {
          print("Cannot perform In App Purchases.")
      }
  }
  
  func productsRequest(request: SKProductsRequest, didReceiveResponse response: SKProductsResponse) {
      if response.invalidProductIdentifiers.count != 0 {
          print("here")
          print(response)
          print(response.invalidProductIdentifiers.description)
          print("here2")
      }
  
      if response.products.count != 0 {
          for product in response.products {
              productsArray.append(product)
              print(productsArray)
          }
      }
      else {
          print("There are no products.")
      }
  }
  </code></pre>