Google checkout: order notification failing

Hello,

I offer Google checkout as a payment method however latelly I keep gettting the following message:

Attention required: order notification failing

We've made several unsuccessful attempts to send order notifications to your notification callback URL, brazilianonlineshop.co.uk/index.php?opti...ckout&tmpl=component As a result, you aren't receiving order status, risk or other notifications.

This URL was copied from the Hikashop payment area as shown by the tutorial, I have copied and pasted it a few times so it is definitely the address that Hikashop is displaying, when I tried to visit this page myself I get the 404 not found error. Any idea what is going on ?


Many thanks