MT | TEC | Fix for Single Event 404s with attachment set in WP Query

tribe_attachment_404_fix.php

<?php

/*
 * Possible solution for Single Event page 404 errors where the WP_Query has an attachment set
 * IMPORTANT: Flush permalinks after pasting this code: http://tri.be/support/documentation/troubleshooting-404-errors/
 * Updated to work with post 3.10 versions
 */
function tribe_attachment_404_fix () {
	if (class_exists('Tribe__Events__Main')) {
		remove_action( 'init', array( Tribe__Events__Main::instance(), 'init' ), 10 );
		add_action( 'init', array( Tribe__Events__Main::instance(), 'init' ), 1 );
	}
}

add_action( 'after_setup_theme', 'tribe_attachment_404_fix' );

I get this message when I try to add this snippet to the functions.php in the child theme though the word press pannel:
No ha sido posible comunicar con el sitio para comprobar los errores fatales, así que el cambio de PHP se ha revertido. Tendrás que subir el cambio a tu archivo PHP por otros medios, como por ejemplo usando SFTP.

I don´t know how to do what its says.

Hi campanillasalsera,
try to delete <?php when copy the snippet in a functions.php that already have it.