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

Call Stack:
    0.0001     234848   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.0001     236136   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    0.0013     270720   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    0.0512    1143096   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    0.0514    1159528   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.9409    1354120   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.9426    1355856   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81