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

Call Stack:
    0.0001     238216   1. {main}() /home/gongquiz_blog/www/index.php:0
    2.2550     239504   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.2552     273672   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.4172    1144456   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.4173    1160880   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.9339    1355424   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.9340    1357152   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81