Edit: The problem is solved, new orders are working again. If you placed a order in the past days and encountered this error, you can finish the order via the payment link in the email you received, or get in touch with us via support@greenhost.net.
We are currently seeing a issue with the payment step when placing a order via our website. This results in a "error 500" in the final steps.
If you saw this error, your order did get stored in our system, please send us a email via support@greenhost.net and we will help you from there.
Our apologies for any delay and confusion.