IAP Question

[ki7a]

Hi!
I am trying for the first time, using the IAP system for GearVR using Unity.
I've managed to make a purchase for a Durable item. but when I get back to the game it crashes. 
My guess is that I can't purchase the same item again, but maybe the crash is because something is wrong with my check script.
I am using the script example from powerballs, with just a bool I've added for my internal check (interntalcheckok). maybe I am doing it all wrong.. Please help!

public void FetchPurchasedProducts()

{

     IAP.GetViewerPurchases().OnComplete(GetViewerPurchasesCallback);

}

void GetViewerPurchasesCallback(Message<PurchaseList> msg)

{

    if (msg.IsError)

    {

         PlatformManager.TerminateWithError(msg);

          return;

     }

    foreach (Purchase p in msg.GetPurchaseList())

    {

        Debug.LogFormat("Purchased: sku:{0} granttime:{1} id:{2}", p.Sku, p.GrantTime, p.ID);

       interntalcheckok = true;

     }

}

private void LaunchCheckoutFlowCallback(Message<Purchase> msg)

{

   if (msg.IsError)

   {

     PlatformManager.TerminateWithError(msg);

     return;

    }

   Purchase p = msg.GetPurchase();

   Debug.Log("purchased " + p.Sku);

   interntalcheckok = true;

}