Help me core problems

[Hostboard]

As Dead Eddie noted vBulletin 4.2.5's last "supported" PHP version is PHP 7.1.x In order to run it on newer versions you will need to update the code to be compliant. You can either do it yourself, hire a PHP programmer (no need to be a VB developer), or use this:

https://vbulletin.org/forum/showthre...highlight=php8

However even after you update the core you will be left with having to update your mods as well.

PHP 7.1 reached EoL back in 2019.
PHP 7.2 reached EoL back in 2020
PHP 7.3 reached EoL back in 2021
PHP 7.4 will reach EoL in 2022
PHP 8.0 will reach EoL in 2023
PHP 8.1 will reach EoL in 2024

As you can see the development cycle is pretty aggressive and the issue will be that shared hosting services will drop support for EoL products noting performance and security issues.

YMMV