just had a call saying site down this is error code
any idea what to do
Warning: require_once(XML/Serializer.php) [function.require-once]: failed to open stream: No such file or directory in /home/lincolns/public_html/admin-files/localizer/LocalizerConfig.php on line 11
Fatal error: require_once() [function.require]: Failed opening required 'XML/Serializer.php' (include_path='/home/lincolns/public_html/library:/home/lincolns/public_html/include:/home/lincolns/public_html/classes:/home/lincolns/public_html/classes/Extension:/home/lincolns/public_html/template_engine/classes:/home/lincolns/public_html/template_engine/metaclasses:/home/lincolns/public_html/application/../library:/home/lincolns/public_html/library:/home/lincolns/public_html/include:.:/usr/lib/php:/usr/local/lib/php') in /home/lincolns/public_html/admin-files/localizer/LocalizerConfig.php on line 11