Warning when using the wpp_get_mostpopular() template tag

Warning: htmlspecialchars(): charset `ANSI_X3.4-1968′ not supported, assuming utf-8 in /xxx/xxx/public_html/wp-content/plugins/wordpress-popular-posts/wordpress-popular-posts.php on line 3383

my code:

<?php
	           global $post;
                  $postcat = get_the_category( $post->ID );
                  $args=array(
                    'cat' => $postcat[0]->term_id, // this is category ID
                    'orderby' => 'views',
					'stats_views' => 1,
					'limit' => 9,
					'order' => ASC,
					'range' => 'weekly',
				        'freshness' => 1,
					'post_type' => 'post',
					'title_length' => 25
                  );
		 wpp_get_mostpopular( $args );
              ?>

i try this code from suport

// Get post data
    global $wp_query;
    $queried_object = $wp_query->get_queried_object();

    // Get post categories
    $categories = get_the_category( $queried_object->ID );

    // WPP paremeters
    $args = array(
        'range' => 'monthly',
        'limit' => 10,
        'post_type' => 'post'
    );

    // Post has at least one category assigned,
    // so let's use its ID to list the most popular
    // from that category
    if ( !empty( $categories ) ) {
        $args['cat'] = $categories[0]->term_id;
    }

    // Display popular posts list
    wpp_get_mostpopular( $args );

but still warning

• This topic was modified 7 years, 6 months ago by Andika.
• This topic was modified 7 years, 6 months ago by Andika.
• This topic was modified 7 years, 6 months ago by Steven Stern (sterndata).