[Thu Jul 04 21:24:52 2013] [error] [client 184.108.40.206] PHP Fatal error: Class name must be a valid object or a string in /var/www/html/chat/library/XenForo/Search/DataHandler/Abstract.php on line 280, referer: http://**/admin.php?tools/cache-rebuild
as one example. Any suggestion as to what might be different on this server? I've got elasticsearch enabled; but I seem to have the same issue even when ES is disabled or removed.
PHP 5.2.17 (cli) (built: Mar 1 2012 16:36:14)
PHP 5.3.25 (cli) (built: May 12 2013 16:33:12)