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

Call Stack:
    0.0001     237264   1. {main}() /home/gongquiz_blog/www/index.php:0
    1.6350     238552   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    1.6544     273136   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    4.4406    1145608   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    4.4430    1162008   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    4.4604    1356624   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    4.4624    1358360   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81