White screen after payment selection

-- url of the page with the problem -- : www.syren.net
-- HikaShop version -- : 2.3.1
-- Joomla version -- : 2.5.22

Hi, suddenly I cannot finish orders anymore. I offer three payment types (wire transfer, PayPal and iDEAL) after selecting one of them the customer gets a white screen. I'm not sure, but as far as I know the only thing changed is the update I made to Hikashop 2.3.1

Hope you can help me soon, because there's no orders at all now

Hi,

Totally white screen is generally a PHP fatal error.
Please check your PHP error log in order to see the error message.
You can otherwise, change the "PHP error message level" to "maximum" in your Joomla global configuration.

Regards,

Thanks for your reply. I set error level to maximum. That showed me quickly something went wrong with the mass actions. I had two similar mass actions and they were both published. I can imagine they were doing the same thing at the same time causing trouble. I unpublished one of them and now the problem is over.