We’ve been running our sites with PayPal.UseInstantNotification=false and relying on customers returning to our site to have aspdnsf create the order. This has worked well for several years up until a few weeks ago when it stopped working.
We now get the Error: Invalid Customer ID or Invalid Order Number and the order is not created in our site.
I tried setting PayPal.UseInstantNotification=true and the order is created but the customer still gets the error. I see in the forums that I can reroute customers to a default page but I would really like to have it work the way we originally had it working because customers get the order number verification.
In reading, it seems that when the customer returns to our site the order should be created. Does anyone know why this might stop working? This was working properly on a dozen sites and they all stopped working at the same time. Could it be a Microsoft update or something caused this to break?
Any help is greatly appreciated.
Tom