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

Call Stack:
    4.7766     238200   1. {main}() /home/gongquiz_blog/www/index.php:0
    4.7767     239488   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    4.7769     273656   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    4.7844    1144432   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    4.7845    1160840   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    4.7859    1355368   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    4.7860    1357096   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81