New Post: Paypal payment

Method:NEvoWeb.Modules.NB_Store.SharedFunctions.GetOptCodeInfo
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 NEvoWeb.Modules.NB_Store.SharedFunctions.GetOptCodeInfo(Int32 PortalID, String OptCode, UserInfo UserInfo, String TextOptions, String TextOptionsXML)
at NEvoWeb.Modules.NB_Store.CurrentCart.ValidateCart(Int32 PortalID, UserInfo UserInfo)
at NEvoWeb.Modules.NB_Store.CartList.PopulateCartList(Int32 OrderID)
at NEvoWeb.Modules.NB_Store.CartList.Page_Load(Object sender, 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.Lo


When doing payment with paypal its showing above error.

Can you pls help me on this task . Its very urgent for my client.

Thanks in advance.