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

Call Stack:
    1.7545     238040   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.7546     239328   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    1.7548     273496   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    1.8523    1144384   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    1.8526    1160776   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    1.8540    1355336   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    1.8541    1357056   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81