Back in January I went through a bunch of troubleshooting with @Hoang Ngo to get this working... See the thread & code that solved the problem here: https://premium.wpmudev.org/forums/topic/add-fields-to-csv-export-membership
Now when I try to export the CSV from an event within Events+ I am getting the following:
Problem Loading Page:
File not found
Firefox can't find the file at http://aaie.net/wp-admin/?eab_export=attendees&event_id=4579.
Check the file name for capitalization or other typing errors.
Check to see if the file was moved, renamed or deleted.
If I remove the code provided by @Hoang Ngo from my functions.php file the export works but only exports the following (user ID, User Name, User Email, Attending, Ticket Count, and Payment). What do I need to do to get this working again?