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

Call Stack:
    0.0001     235504   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.0002     236792   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    0.0028     271376   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.2224    1143808   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.2226    1160256   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.2516    1354888   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.2517    1356624   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81