I'm trying to upgrade my InvisionCommunity forum from version 4.4.2 to 4.7.18, but I'm encountering issues with PHP compatibility.
When I switch to PHP 8.1 (which is required for 4.7.18), my forum stops working, and I can't access the admin/upgrade page. On the other hand, without switching to PHP 8.1, I can't proceed with the upgrade.
I'm stuck and unsure how to move forward with this upgrade. What steps should I take to successfully update from 4.4.2 to 4.7.18? Any advice or guidance would be greatly appreciated.