Trouble checking out

-- url of the page with the problem -- : fearlessrider.com
-- HikaShop version -- : 2.5.0
-- Joomla version -- : 3.2.2

I'm having a lot of problems with this shopping cart and I'm not really sure how to fix. People will try to check out and the site goes blank. If I disable HikaShop, the site will come back. I look at all the setting, do a ton of testing and everything will seem fine. But then my client gets an email saying a customer can not access the website again. The problem is, it's an intermittent - it will fine, will be able to complete a transaction, then someone tries to buy something and it stops working.

Hi,

When you have a blank page it is generally caused by a PHP fatal error.
At this moment you can check your PHP error log in order to see if you have recent fatal errors in that log.
You can also see to activate temporally the Joomla debug mode or to change the "error reporting" to "maximum" in your Joomla global configuration ; it should at this moment display the errors directly in the page instead of giving a blank page.

Thanks to the error message ; it will be easier to understand what is the issue and fix it.

Regards,