New Post: Paypal showing Status "Payment not verified"

ok..

when i changed url of paypal.gateway then no paypal button image showing with "submit query".. when we click it showing below error:

Error: PLEASE NOTE: Your credit card charge will appear as Always Aware. Thank you for your business! is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: 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.Gateway.GatewayPayPal.StringListReplace(String value, String searchfor, String replacewith) at NEvoWeb.Modules.NB_Store.Gateway.GatewayPayPal.PayPalEncode(String value) at NEvoWeb.Modules.NB_Store.Gateway.GatewayPayPal.SetBankRemotePost(Int32 PortalID, Int32 OrderID, String Lang, HttpRequest Request) at NEvoWeb.Modules.NB_Store.CheckOut.GatewayRedirect() at NEvoWeb.Modules.NB_Store.CheckOut.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---

Please help how to fix this issue.