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

Call Stack:
    5.0212     234320   1. {main}() /home/gongquiz_blog/www/index.php:0
    5.0212     235608   2. require('/home/gongquiz_blog/www/_common.php') /home/gongquiz_blog/www/index.php:2
    5.0218     270192   3. include_once('/home/gongquiz_blog/lib/common.php') /home/gongquiz_blog/www/_common.php:3
    7.0317    1142840   4. dbConn->__construct() /home/gongquiz_blog/lib/common.php:68
    7.0321    1159240   5. log_e() /home/gongquiz_blog/lib/common/dbConn.class.php:48
    8.3845    1353904   6. error_::log_e() /home/gongquiz_blog/lib/libf.php:563
    8.3847    1355640   7. error_::log() /home/gongquiz_blog/lib/common/error_.class.php:81