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

Call Stack:
    1.0195     238552   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.4961     239840   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    2.5306     274008   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    3.0529    1144608   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    3.0533    1161040   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    3.0554    1355608   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    3.0556    1357336   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81