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

Call Stack:
    0.0001     238440   1. {main}() /home/gongquiz_blog/www/index.php:0
    3.3874     239728   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    3.3881     273896   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    6.9536    1144704   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    6.9539    1161104   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    6.9572    1355608   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    6.9577    1357336   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81