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

Call Stack:
    3.6699     237816   1. {main}() /home/gongquiz_blog/www/index.php:0
    3.6700     239104   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    3.6706     273688   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    3.6789    1146184   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    3.6790    1162600   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.6806    1357256   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.6808    1359008   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81