Event Registration is a great WordPress plugin that allows you to manage events on your WordPress website, but I noticed a bug I wanted to blog about. I added some 'Questions' to the registration form and received this error message:

Error message

"There was an error in your submission, please try again. The attendee was not saved!. ..Now returning you to attendee list.. Now adding extra question responses. Value String - The attendee extra questions responses have been added. ...Now returning you to attendee list..

Explination/Solution

It turns out that the error is caused when you try to update attendee information of attendees that were created prior to adding custom questions. To work around this error message, simply recreate the attendee with the same information.