Worth upgrading from 4.2.3 to 5 ?

[Rory2000]

Hi,

I have a larger forum 1.2m posts and all is working great, although not runing PHP 7 so no doubt a speed improvment to be had there.

In short, its been fine tuned over the years, and it works... is there any benefit in upgrading to latest version 5 ?

[Wayne Luke]

The #1 benefit will be server security. vBulletin 4.2.3 cannot run on the latest secure software. Especially PHP, the entire engine everything runs on. Even versions of PHP 7 are being marked end of life these days. PHP 7.2 (not supported by vBulletin 4.X) goes end of life this year.

Looking at your site, it looks like a fairly standard install without a lot of third-party addons. So you should only gain features, not lose anything.