Hi.
I have the cart hooked up to the paypal sandbox.  The shopper can add items, the cart adds it up, the shopper ads their details and clicks pay.  The shopper is now transported to the paypal site and completes the transaction.  So far all is well.  Now the shopper clicks the "Return to merchant" site.  The shopper is returned to my to the Cart page on my site but an error is reported "Object reference not set to an instance of an object." (<customErrors mode="Off"/>) and add to that the all of the items are still listed in the cart.

The thing is that I don't really know where to begin to debug this error.  Can you tell me anything about the values returned from PayPal and how to debug them?

Ray
(What I'd give for a program flow diagram right now)


RawURL: /mysite/Default.aspx?TabId=54&ctl=Checkout&mid=377&PayPalExit=return
AbsoluteURL: /mysite/Default.aspx
AbsoluteURLReferrer:
UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: 56cf343c-863f-4770-9bc4-ce1e3750af14
InnerException: Object reference not set to an instance of an object.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: DotNetNuke.Services.Exceptions.Exceptions.ProcessModuleLoadException
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Services.Exceptions.Exceptions.ProcessModuleLoadException(PortalModuleBase ctrlModule, Exception exc) at DotNetNuke.Modules.Store.Cart.PayPalPayment.Page_Load(Object sender, EventArgs e) at System.Web.UI.Control.OnLoad(EventArgs e) at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Control.LoadRecursive() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---

Ok so I was wrong again.  If I hack the code and replace

payPalURL += "&return=" + HTTPPOSTEncode(returnURL);

   with

payPalURL += "&return=http://www.ubsnaps.com/Downloads/tabid/62/Default.aspx";

it doesn't through the error but it also doesn't update the database so it's a trade off that's no good.

I need to know what object is it looking for when it returns from paypal.

Anyone?