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

Call Stack:
    1.0228     236448   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.0229     237736   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    1.0234     271904   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.8307    1142544   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.8309    1158976   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.8399    1353448   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.8401    1355192   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81