Empty error box on checkout page

Hi, I have made a simple store using woocommerce but while placing an order it shows an empty error box on top of the checkout page all the plugins are deactivated and the theme is set the default. Iam confused about what caused the error I have googled every possibility.
Please visit the link attached
Place an order
You will see an empty error box on top of the checkout page
Remember other than woocommerce no plugin is activated.

The page I need help with: [log in to see the link]