Fatal error: Class 'Client' not found in /home/gongquiz_blog/lib/common/error_.class.php on line 92

Call Stack:
    0.0001     237832   1. {main}() /home/gongquiz_blog/www/index.php:0
    2.3591     239120   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.3593     273288   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.3666    1144040   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.3667    1160472   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.3681    1354976   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.3682    1356704   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81