Database error

Database error in vBulletin 3.6.8:

Invalid SQL:

UPDATE session
SET lastactivity = 1194825471, location = '/arcade.php?', inforum = 0, inthread = 0, incalendar = 0, badlocation = 0
WHERE sessionhash = 'f54d435f51f86d2d73a5e428b87fb279';

MySQL Error : MySQL server has gone away
Error Number : 2006
Date : Sunday, November 11th 2007 @ 04:59:28 PM
Script :
Referrer :
IP Address :
Username :
Classname :

My arcade stopped loading all of a sudden and I received that database error via e-mail. Any help you can offer? I've been running the arcade for around a month and a half without error before receiving this message.

[MrZeropage]

read the error-message:

MySQL server has gone away

[Deadman_014]

any help on how I can fix that though? The rest of the site still works fine.

[MrZeropage]

this is not part of the arcade, this is for vB-sessiondata ...