Since Zendesk's API validations and error cases are no documented, it is possible that the support app's validations let invalid requests slip through. This means that it's not possible to raise a ticket from the user's request. Prior to this change, such cases would generate a standard Rails 500 error. After this change, the user sees a much clearer error message and receives a text representation of the ticket that was going to be raised, in case they would like to review it or forward it on via email.
For requests from users who are already in Zendesk, a name is not necessary (just the email). Even if a name is provided on the ticket, Zendesk ignores it. For users not yet in Zendesk, a name must be provided on the ticket. Since the forms no longer ask for the name (and very soon the name will be coming from SSO), Zendesk rejects tickets from new requesters. The stop-gap solution is to use the email address as the name.