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

Call Stack:
    3.4106     232952   1. {main}() /home/gongquiz_blog/www/index.php:0
    3.7490     234240   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    3.7493     268824   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    3.8224    1141416   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    4.6165    1157824   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    4.7263    1350928   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:564
    4.7845    1352632   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81