sitemap oluştururken databasa hatası alıyorum. neden olabilir?

Database error in vBulletin 4.2.0:

Invalid SQL:
DELETE FROM adminutil WHERE title = 'sitemapsession';

MySQL Error : MySQL server has gone away
Error Number : 2006
Request Date : Friday, May 23rd 2014 @ 08:19:32 AM
Error Date : Friday, May 23rd 2014 @ 08:20:02 AM
Script : http://www.siteadresi.com/admincp/sitemap.php?do=dobuildsitemap
Referrer : http://www.ssiteadresi.com/admincp/s...dobuildsitemap
IP Address : 78.189.202.196
Username : admin
Classname : vB_Database
MySQL Version :
site adresi: www.forum-enter.com