rmegliorino

This works:

function exclude_wpdmpro_type() {
	global $wp_post_types;
	if ( post_type_exists( 'wpdmpro' ) ) {
		// exclude from search results
		$wp_post_types['wpdmpro']->exclude_from_search = true;
	}
}

Just make sure to double check your single quotes because the WYSIWYG Editor sometimes converts them to real text quotes