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

Call Stack:
    0.0001     235984   1. {main}() /home/gongquiz_blog/www/index.php:0
    2.1563     237272   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.1566     271440   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.1639    1142064   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.1640    1158480   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.1654    1352976   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.1655    1354720   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81