Can’t add widgets while customizing wordpress

here is my code in functions.php

function themename_widgets_init() {
register_sidebar( array(
'name' => __( 'Primary Sidebar', 'theme_name' ),
'id' => 'sidebar-1',
'before_widget' => '<aside id="%1$s" class="widget %2$s">',
'after_widget' => '</aside>',
'before_title' => '<h1 class="widget-title">',
'after_title' => '</h1>',
) );

}
add_action( 'widgets_init', 'themename_widgets_init' );
here is the code in my sidebar.php

<div id="sidebar-primary" class="sidebar">
<?php dynamic_sidebar( 'sidebar-1' ); ?>
</div>
and the code in my footer.php to display my sidebar:-

<?php get_sidebar(); ?>
When I am trying to customize the sidebar from dashboard there I am able to add and remove widgets but when I am trying to add widgets from live website(i.e from the left panel which provides options for customization and changes are appeared on the right panel at same time ) there I am getting this message ‘There are no widget areas on the page shown, however other pages in this theme do have them.’ So what is wrong that I am doing here that I am able to add widgets from dashboard and can’t add while customizing it on the live website ? Thanks in advance.