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

Call Stack:
    0.2135     236976   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.5137     238264   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.1865     272848   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    3.9988    1143560   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    3.9999    1159992   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    4.0029    1354640   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    4.0031    1356376   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81