I am getting error on checkout page:
Your card has been declined. Please re-enter your card information, try another card, or contact the store owner for assistance.
and the URL of the page is : site.com/index.php?main_page=checkout&fecaction=null
I am using Securepay payment module and credit card is verified with them.
If you are testing, you need to set SecurePay in test mode (under admin->modules->payment). Otherwise a test card will not be accepted.