[Mariner1]

Hi. This has been working fine until a few days ago.When trying to do backups now i get this error in admincp

Database error in vBulletin 4.2.2:

Invalid SQL:
OPTIMIZE TABLE `filedata`;

MySQL Error : MySQL server has gone away
Error Number : 2006
Request Date : Friday, January 2nd 2015 @ 05:54:35 AM
Error Date : Friday, January 2nd 2015 @ 05:55:08 AM
Script : http://www.xxxxxxxxxxx.com/admincp/c...cron&cronid=95
Referrer : http://www.xxxxxxxxxxxx.com/admincp/....php?do=modify
IP Address : xx.x.xxx.xx
Username : xxxxxxx
Classname : vB_Database
MySQL Version :

Any idea what this is and how to fix it pls