Setting up Sendy on Mac OS localhost

I followed the Get Started guide but am getting a 500 Error when loading the sendy home page via
http://localhost/sendy

here is my config file:

<?php
//----------------------------------------------------------------------------------//
// COMPULSORY SETTINGS
//----------------------------------------------------------------------------------//

/*  Set the URL to your Sendy installation (without the trailing slash) */
define('APP_PATH', 'http://localhost/sendy');

/*  MySQL database connection credentials (please place values between the apostrophes) */
$dbHost = 'localhost'; //MySQL Hostname
$dbUser = 'sendy'; //MySQL Username
$dbPass = 'sendy'; //MySQL Password
$dbName = 'sendy'; //MySQL Database Name


//----------------------------------------------------------------------------------//  
//                                OPTIONAL SETTINGS
//----------------------------------------------------------------------------------//  

/* 
    Change the database character set to something that supports the language you'll
    be using. Example, set this to utf16 if you use Chinese or Vietnamese characters
*/
$charset = 'utf8';

/*  Set this if you use a non standard MySQL port.  */
$dbPort = 3306; 

/*  Domain of cookie (99.99% chance you don't need to edit this at all)  */
define('COOKIE_DOMAIN', '');

//----------------------------------------------------------------------------------//