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

Call Stack:
    0.0001     235648   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.0002     236936   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    0.0004     271520   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    0.0092    1144048   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    0.0093    1160512   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    0.0109    1353592   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:564
    0.0110    1355304   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81