Coding Error

I get an error trying to use this:

Warning: simplexml_load_string() [function.simplexml-load-string]: Entity: line 1: parser error : Start tag expected, '<' not found in /home/content/m/a/r/marcjoseph/html/content/plugins/youtube-sidebar-widget/youtube-sidebar-widget.php on line 82

Warning: simplexml_load_string() [function.simplexml-load-string]: Invalid request URI in /home/content/m/a/r/marcjoseph/html/content/plugins/youtube-sidebar-widget/youtube-sidebar-widget.php on line 82

Warning: simplexml_load_string() [function.simplexml-load-string]: ^ in /home/content/m/a/r/marcjoseph/html/content/plugins/youtube-sidebar-widget/youtube-sidebar-widget.php on line 82
Service Unavailable.

http://ww.wp.xz.cn/extend/plugins/youtube-sidebar-widget/