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

Call Stack:
    1.4522     236736   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.4523     238024   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    1.4525     272192   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.7643    1142816   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.7647    1159216   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.7729    1353736   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.7730    1355472   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81