With this bridge, the date field on the payment2.asp (or .aspx if using .NET) must be input by the customer in the format mm/yy. If it is not entered exactly this way, the page will fail.
In FrontPage, edit the payment2.asp (or .aspx if using .NET) page next to the Expiration Date field with an example of how to correctly enter the expiration date. You can also use Form Field validation to help ensure the correct format by right clicking on the field and selecting Form Field Properties.