Paypal error on Auto Return

I have my paypal setup and test with Paypal sandbox and everything working as expected but when we put it live, we encountered an error every time  after the paypal when returning to our website. Further check in the Nopcommerce Log we have got something like below, do anyone know what's wrong with that?


The level of log entry.Log level:  Error
The log entry message.Short message:  The remote server returned an error: (403) Forbidden.
The details for the log entry.Full message:  System.Net.WebException: The remote server returned an error: (403) Forbidden. at System.Net.HttpWebRequest.GetResponse() at Nop.Plugin.Payments.PayPalStandard.PayPalStandardPaymentProcessor.VerifyIPN(String formString, Dictionary`2& values) at Nop.Plugin.Payments.PayPalStandard.Controllers.PaymentPayPalStandardController.IPNHandler() at lambda_method(Closure , ControllerBase , Object[] ) at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<BeginInvokeSynchronousActionMethod>b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3d() at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.<InvokeActionMethodFilterAsynchronouslyRecursive>b__3f() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass33.<BeginInvokeActionMethodWithFilters>b__32(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<>c__DisplayClass2b.<BeginInvokeAction>b__1c() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass21.<BeginInvokeAction>b__1e(IAsyncResult asyncResult) at System.Web.Mvc.Controller.<BeginExecuteCore>b__1d(IAsyncResult asyncResult, ExecuteCoreState innerState) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) at System.Web.Mvc.MvcHandler.<BeginProcessRequest>b__5(IAsyncResult asyncResult, ProcessRequestState innerState) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)
IP address of the machine that caused the exception.IP address:  173.0.81.1

Can someone help me on this

Still hoping someone can help on this

Can you double check if both urls are correct as bellow?

PayPalStandardPaymentProcessor.cs

  private string GetPaypalUrl()
        {
            return _paypalStandardPaymentSettings.UseSandbox ? "https://www.sandbox.paypal.com/us/cgi-bin/webscr" :
                "https://www.paypal.com/us/cgi-bin/webscr";
        }

I did not modified the source code, i downloaded the compiled version to setup the web store. It's been working for so long until recently it just stop working and getting the error in the first post.

Does anyone offering paid support to this specific issue?

anyone?

Do you have the correct IPN url in production? Test it to see if it can be reached.

The IPN url is the same i used to test it in the sandbox and live but i have no idea why it's only works in sandbox.

Please have a look at https://www.nopcommerce.com/boards/t/32372/paypal-standard-live-mode-ipn-pdt-verification-return-403-forbidden.aspx