Error log report for 3.9

Hi Sylvia,
My error log is returning “Undefined Offset” for the following lines near the end of external-videos.php:

The undefined offset seems to be the offset for the $host, $duration and $thumbnail, maybe the stored values are not arrays?

add_action('manage_posts_custom_column', 'sp_external_videos_custom_columns');
function sp_external_videos_custom_columns($column_name)
{
    global $post;
    $duration  = get_post_meta($post->ID, 'duration');
    $host      = get_post_meta($post->ID, 'host_id');
    $thumbnail = get_post_meta($post->ID, 'thumbnail_url');

    switch($column_name) {
    case 'ID':
        echo $post->ID;
        break;

    case 'thumbnail':
        echo "<img src='".$thumbnail[0]."' width='120px' height='90px'/>";
        break;

    case 'duration':
        echo $duration[0];
        break;

    case 'published':
        echo $post->post_date;
        break;

    case 'host':
        echo $host[0];
        break;

It’s just those three variables with the [0] offset producing the errors.

https://wordpress.org/plugins/external-videos/