[jeremybivaud]

There is no custom code.
I just used the extra field , file. It s supposed to work.

And on the front end, I got this when I display the uploaded file path :
http://www.documentor.com.au/wordpress/wp-content/uploads/boardingPass-2016072807431691628792.pdf
That file not exist on the server.
I displayed error WP log message but no indication at all.

Do you know where the upload file function is implemented in the core ?