Uncaught Error: Class ‘LTG_G3_Slider’ not found

?php
/**
 * Lightning G3 index.php common template-file
 *
 * @package vektor-inc/lightning
 */

use VektorInc\VK_Breadcrumb\VkBreadcrumb;

?><?php lightning_get_template_part( 'header' ); ?>

<?php
do_action( 'lightning_site_header_before', 'lightning_site_header_before' );
if ( apply_filters( 'lightning_is_site_header', true, 'site_header' ) ) {
	lightning_get_template_part( 'template-parts/site-header' );
}
do_action( 'lightning_site_header_after', 'lightning_site_header_after' );
?>

<?php
if ( is_front_page() ) {
	if ( apply_filters( 'lightning_default_slide_display', true ) ) {
 		LTG_G3_Slider::display_html();
	}
}
?>

<?php if ( ! is_front_page() ) : ?>

	<?php
	do_action( 'lightning_page_header_before', 'lightning_page_header_before' );
	if ( apply_filters( 'lightning_is_page_header', true, 'page_header' ) ) {
		lightning_get_template_part( 'template-parts/page-header' );
	}
	do_action( 'lightning_page_header_after', 'lightning_page_header_after' );
	?>

	<?php
	do_action( 'lightning_breadcrumb_before', 'lightning_breadcrumb_before' );
	if ( apply_filters( 'lightning_is_breadcrumb_position_normal', true, 'breadcrumb_position_normal' ) ) {
		if ( apply_filters( 'lightning_is_breadcrumb', true, 'breadcrumb' ) ) {
			$vk_breadcrumb      = new VkBreadcrumb();
			$breadcrumb_options = array(
				'id_outer'        => 'breadcrumb',
				'class_outer'     => 'breadcrumb',
				'class_inner'     => 'container',
				'class_list'      => 'breadcrumb-list',
				'class_list_item' => 'breadcrumb-list__item',
			);
			$vk_breadcrumb->the_breadcrumb( $breadcrumb_options );
		}
	}
	do_action( 'lightning_breadcrumb_after', 'lightning_breadcrumb_after' );
	?>

<?php endif; ?>

<?php do_action( 'lightning_site_body_before', 'lightning_site_body_before' ); ?>

<div class="<?php lightning_the_class_name( 'site-body' ); ?>">
	<?php do_action( 'lightning_site_body_prepend', 'lightning_site_body_prepend' ); ?>
	<div class="<?php lightning_the_class_name( 'site-body-container' ); ?> container">

		<div class="<?php lightning_the_class_name( 'main-section' ); ?>" id="main" role="main">
			<?php do_action( 'lightning_main_section_prepend', 'lightning_main_section_prepend' ); ?>

			<?php
			if ( apply_filters( 'lightning_is_main_section_template', true, 'main_section_template' ) ) {
				if ( lightning_is_woo_page() ) {
					lightning_get_template_part( 'template-parts/main-woocommerce' );
				} else {
					if ( apply_filters( 'lightning_is_singular', is_singular() ) ) {
						lightning_get_template_part( 'template-parts/main-singular' );
					} else {
						if ( is_404() ) {
							lightning_get_template_part( 'template-parts/main-404' );
						} else {
							lightning_get_template_part( 'template-parts/main-archive' );
						}
					}
				}
			}
			?>

			<?php do_action( 'lightning_main_section_append', 'lightning_main_section_append' ); ?>
		</div><!-- [ /.main-section ] -->

		<?php
		do_action( 'lightning_sub_section_before', 'lightning_sub_section_before' );
		if ( lightning_is_subsection() ) {
			if ( lightning_is_woo_page() ) {
				do_action( 'woocommerce_sidebar' );
			} else {
				lightning_get_template_part( 'sidebar', get_post_type() );
			}
		}
		do_action( 'lightning_sub_section_after', 'lightning_sub_section_after' );
		?>

	</div><!-- [ /.site-body-container ] -->

	<?php do_action( 'lightning_site_body_append', 'lightning_site_body_append' ); ?>

</div><!-- [ /.site-body ] -->

<?php if ( is_active_sidebar( 'footer-before-widget' ) ) : ?>
<div class="site-body-bottom">
	<div class="container">
		<?php dynamic_sidebar( 'footer-before-widget' ); ?>
	</div>
</div>
<?php endif; ?>

<?php
do_action( 'lightning_site_footer_before', 'lightning_site_footer_before' );
if ( apply_filters( 'lightning_is_site_footer', true, 'site_footer' ) ) {
	lightning_get_template_part( 'template-parts/site-footer' );
}
do_action( 'lightning_site_footer_after', 'lightning_site_footer_after' );
?>

<?php lightning_get_template_part( 'footer' ); ?>

Uncaught Error: Class ‘LTG_G3_Slider’ not found

突然上記のようなエラーメッセージが表示されるようになりました

テーマはLightningを使用しております
早急に解決したいです