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

Call Stack:
    2.8264     232984   1. {main}() /home/gongquiz_blog/www/index.php:0
    2.8264     234272   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.8608     268856   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.8688    1141520   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.8690    1157920   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.8969    1350992   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:564
    2.8971    1352704   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81