all of a sudden I can not access my payment/upgrade site

Hi,

10 min. ago everything was working fine - and I wanted to test my payment gateway. So I created a new account (just like my members should) and payed via Paypal (just like my members). I got to a page with the text; finalizing your payment… that fine. I did not confirm any email yet for the payment.

Then I tried to login to another test account - and everything on the site is working, except for the payment site.. this is after another "test user" payed.

my upgrade/payment site is called: twiqstudio.com/upgrade

The site where the pro site modules and payment should be shown. the site just go blank and the top menu disappear. What is wrong??????????? feeling scared
Something in the code??? what to do?