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

Call Stack:
    0.0001     238904   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.5381     240192   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    1.5384     274360   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    3.4574    1145032   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    3.4576    1161448   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.5085    1355888   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.5143    1357616   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81