Can't show payment form

Hi,

I have a big problem....
When I setting a form, and link to a menu.
There is a blank page, and show Internal Server Error(404).

When I test it in a test site, It's OK.
I don't know what happen.
Please help.

see the
akhostelbkk.com/

top menu "TEST"

Thank you very much!

Jerry

Hi Jerry

Please send an email to services@joomdonation.com sending me administrator and FTP account of your site so that I can check and solve it for you.

Tuan