This article covers situations in which Advanced Confirmation messages are not properly referencing the Profile Fields of the supporter when the confirmation is sent.
Heavily customized mailing content can cause issues referencing these fields. Replacing these Profile Fields with corresponding Event Fields may provide relief. The content may need to be simplified and recreated.
Please review the HTML content of the mailing for any scripts.
If you would like assistance reviewing the mailing HTML, chat with Support and reference this article.