Fixes a compatibility issue between WooCommerce 2.3.x and WooCommerce Tickets 3.9

woo231-fix.php

<?php
// -----------------------------------------------------------------------------
// The code below this comment should be added to the theme's functions.php file
// -----------------------------------------------------------------------------


// Compatibility fix to help run WooCommerce Tickets 3.9 with WooCommerce 2.3.x
if ( class_exists( 'TribeWooTickets' ) ) {
	// Form reference to ticket processing callback
	$wootickets = TribeWooTickets::get_instance();
	$callback = array( $wootickets, 'process_front_end_tickets_form' );

	// Switch to a later action
	remove_action( 'init', $callback );
	add_action( 'wp_loaded', $callback );
}