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

Call Stack:
    0.0001     235568   1. {main}() /home/gongquiz_blog/www/index.php:0
    0.0003     236856   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    0.0006     271024   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    0.2299    1141816   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    0.2302    1158216   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    0.2326    1352704   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    0.2328    1354424   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81