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

Call Stack:
    0.0001     238696   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.0001     239984   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    0.0003     274152   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    2.1773    1144808   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    2.1775    1161216   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    2.1789    1355760   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    2.1790    1357480   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81