Was trying to recruit a friend, and hi was unable to signup for DDO.
Did check it for myself, and failed to signup too.
After posting the form, signup.ddo.com always responds with error 500.

Code:
https://signup.ddo.com/ddo.php?ftui=DDOBlackDragon&referral=&utm_source=&utm_campaign=&utm_medium=&abrs=1&msc=0&lang=en-US&success=1

This page isn’t working
signup.ddo.com is currently unable to handle this request.
HTTP ERROR 500