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

Call Stack:
    0.0001     238472   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.2834     239760   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.6019     273928   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.6092    1144680   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.6093    1161152   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.9198    1355688   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.9200    1357416   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81