Check out process won't work anymore

-- url of the page with the problem -- : www.awards4u.ca
-- HikaShop version -- : 2.3.4
-- Joomla version -- : 2.5.8

Hi,

My check out won't work anymore. It worked before and now it's won't work. So when someone clicks on finish it just stays on the page! It won't process. The customer doesn't get an e-mail and I don't get anything?

Thanks,
Mohammed

Hi,

What have been changed between when it was working and now ?
Workflow edited, update, etc ?