What does this error mean?
 

This is the second e-mail I have gotten from one of my members reporting this feedback:

Database error in vBulletin 3.6.4:

Invalid SQL:

UPDATE session
SET lastactivity = 1210542088, incalendar = 0, badlocation = 0
WHERE sessionhash = '8fa15cae83f7bc22992028709c8dd950';

MySQL Error : MySQL server has gone away
Error Number : 2006
Date : Sunday, May 11th 2008 @ 04:42:05 PM
Script : http://lonman06forums.com/attachment...8&d=1210453369
Referrer : http://lonman06forums.com/showthread.php?p=785#post785

Can anyone explain what this means? Thanks in advance!

That means your MySQL server timed out and closed the connection to the database. A refresh of the page often resolves the problem.

Oh ok, so nothing I need to fix then?

Not unless you keep getting them.