我的插件破坏了wordpress编辑图片预览

我有一个像仪表板一样的wordpress插件。。。问题是，我的代码中有一些东西破坏了编辑图像wordpress的功能，但我在代码中找不到问题，我尝试了关闭和不关闭

       <?php 
    /*
    Plugin Name: SIG DASHBOARD
    Plugin URI: 
    Description: DASHBOARD SIG
    Author: bruno alexandre
    Version: 1.1
    Author URI: 
    */
?>
<?php
function sig_load_plugin_css() {
  $plugin_url = plugin_dir_url( __FILE__ );
  wp_enqueue_style( 'style1', $plugin_url . 'css/style_dash.css' ); }
  add_action( 'admin_head', 'sig_load_plugin_css' );
// load css ** end 

add_action('wp_dashboard_setup', 'add_custom_dashboard_widget4');
function custom_dashboard_widget4() { ?>

<div class="boxes1">
<h2>Toppromomkt</h2> <p>Website</p>
<img src="http://www.toppromomkt.com/wp-content/themes/toppromo/images/adm_logo_toppromo.png">
<ul> <li> <a href='http://www.toppromomkt.com/'> <img class='list1ico' src='http://www.toppromomkt.com/wp-content/themes/toppromo/images/arrowr.png'>Ver Site</a></li><li><a href='http://www.toppromomkt.com/wp-login.php?action=logout&_wpnonce=656cdaeabc'><img class='list1ico' src='http://www.toppromomkt.com/wp-content/themes/toppromo/images/arrowr.png'>Logout</a></li></ul>
<div id="ultimos">
<h3>Design e Programaçao </h3><br><span>D.er Bruno Alexandre <br>  www.kilt-design.com <br>bugs and reports at brunoalex9@msn.com</span>
</div></div>


<?php  }
function add_custom_dashboard_widget4() {
    wp_add_dashboard_widget('custom_dashboard_widget4', 'SIG - Sistema Integrado de Gestão - D.er Bruno Alexandre (design-it-now@hotmail.com)', 'custom_dashboard_widget4');
}

?>