CMemCache blank page

Hello. Im try to enable the memcache or memcached in Yii, but after enable in config, site show blank page, without any php error. Firefox console: internal server error. All coponents memcache installed on server, and work.

_setting.php


'cache' => 

    array (

      'class' => 'CMemCache',

      'servers'=>array(

          array('host'=>'localhost', 'port'=>11211, 'weight'=>60),

do you have php errors enabled?