Multi-page Toolkit Plugin is not working

Multi-page Toolkit is a very useful plugin especially for review sites.

It displays multiple webpages in a dropdown box each with a Page Title for you to select and view. After a longish search i didn’t find any other plugins that display multiple pages in a dropdown box.

The problem is Multi-page Toolkit is a broken plugin for WP 3.9. It has worked in previous versions despite being a older plugin from 2008.

It installs fine but in Tiny-MCE when pressing Page Title button, it pops up a small non usable dialog box.

Could someone please look at the plugin if possible. I include the Tiny MCE code from the plugin if that helps. How can i get this plugin working with WordPress 3.9+

Many Thanks.

// TinyMCE stuff

// init process for button control

function my_refresh_mce($ver) {
   $ver += 3; // or $ver .= 3; or ++$ver; etc.
   return $ver;
}
add_filter('tiny_mce_version', 'my_refresh_mce');

function multipage_addbuttons() {
 	// Check if WordPress 2.5+ (TinyMCE 3.x)
	global $wp_db_version;
	if ( $wp_db_version > 6124 ) {
   	// Add only in Rich Editor mode
    add_filter("mce_external_plugins", "add_multipagebuttons_plugin");
   	add_filter('mce_buttons', 'register_multipagebuttons'); }
}

function register_multipagebuttons($buttons) {
   	array_push($buttons, "separator", "nextpage", "pagetitle");
   	return $buttons;
}

// Load the TinyMCE plugin : editor_plugin.js (wp2.5)
function add_multipagebuttons_plugin($plugin_array) {
	$plugin_array['multipagebuttons'] = get_option( 'siteurl' ) . '/wp-content/plugins/multi-page-toolkit/buttons/editor_plugin.js';
	return $plugin_array;

}