I am new to wordpress and was encountered the Warning: Undefined array key 5408 in C:\xampp\htdocs\Bridge\wp-includes\nav-menu-template.php on line 210, is there any solution for me to fix this issue?

// Set up the $menu_item variables.<br /> _wp_menu_item_classes_by_context( $menu_items );</p> <p> $sorted_menu_items = array();<br /> $menu_items_tree = array();<br /> $menu_items_with_children = array();<br /> foreach ( (array) $menu_items as $menu_item ) {<br /> $sorted_menu_items[ $menu_item->menu_order ] = $menu_item;<br /> $menu_items_tree[ $menu_item->ID ] = $menu_item->menu_item_parent;<br /> if ( $menu_item->menu_item_parent ) {<br /> $menu_items_with_children[ $menu_item->menu_item_parent ] = 1;<br /> }</p> <p> // Calculate the depth of each menu item with children<br /> foreach ( $menu_items_with_children as $menu_item_key => &$menu_item_depth ) {<br /> $menu_item_parent = $menu_items_tree[ $menu_item_key ];<br /> while ( $menu_item_parent ) {<br /> $menu_item_depth = $menu_item_depth + 1;<br /> $menu_item_parent = $menu_items_tree[ $menu_item_parent ];<br /> }<br /> }<br /> }</p> <p>