Firstly, it's much more user-friendly on these forums to just post any code here as text within [code]...[/code]
tags.
If you are testing this in your old 5.4 environment, that's likely the problem, since password_hash()
was introduced in PHP 5.5. If that's not it, put in this code as the first thing after the opening PHP tag:
<?php
ini_set('display_errors', true);
error_reporting(E_ALL);