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Database error in vBulletin 3.8.5:

Invalid SQL:
SELECT userid from post where threadid='9040'  AND userid=1;

MySQL Error   : MySQL server has gone away
Error Number  : 2006
Request Date  : Thursday, May 19th 2011 @ 04:05:16 PM
Error Date    : Thursday, May 19th 2011 @ 04:05:41 PM
Script        : [URL]http://www.king-ms.com/vb/showthread.php?p=35823[/URL]
Referrer      : [URL]http://www.king-ms.com/vb/newthread.php?do=newthread&f=37[/URL]
IP Address    :*************
Username      : ******
Classname     : vB_Database
MySQL Version :