I am trying to get the registrant details for a registrant but am receiving a (500) Internal Server Error. I first get a list of events and parse the event id for the event I am interested in. I then get a list of registrants based on the event id. This all works great.
That error may be specific to some contact information. Can you please use a REST client and save the RCQ and send it to firstname.lastname@example.org so we can evaluate exactly what is going on. Once we have the RCQ file we can check your request against our internal accounts to see what exactly is going on.