How secure is v3.8.3

[Simon Lloyd]

That error shown there is NOT the reason the server overloaded, that simply shows that you've reached the limit set on your server or imposed by your hosts on the max number of connections you can have at any one time, it doesn't mean that each single connection is a single person, here's some documentation http://dev.mysql.com/doc/refman//5.5...nnections.html

As for the security, the patches are for the vb3.8.x series, you can see all the security patches available to you in your members area at vb.com, download them and apply them and you'll be good as long as you've followed all the other advice on securing your forum