So I recently purchased a server that had php 5 instead of php 4.3.11 on the machine my forums are on.

I'm having some problems downgrading my php version, so I was wondering if I upgrade my ubb forums from 6.4 to a higher version, will it become compatible with php 5.0?

UBB7 is compatible with PHP5; I'd imagine UBB.T6.5.5 should be compatible as well.

I believe I ran it on php5, but that was a long time ago...