Pluggable.php error – Reviewgine-Affiliate Theme

HAs anyone seem this error since the latest WP update ? I’ve been working on this site only my local wamp but when I moved it to the live server I’ve started to get this error – Warning: Cannot modify header information – headers already sent by (output started at XXXXXXX/wp-content/themes/reviewgine-affiliate/functions.php:429) in XXXXXXX/wp-includes/pluggable.php on line 1196

429 in fuctions.php is this;

<?php

/* Include custom css */
add_action( ‘wp_head’, ‘review_custom_css_hook’ );
function review_custom_css_hook( ) {
# get theme options
?>

And before this I got a sidebar error which I fixed by adding .$i to the function – ‘id’ => ‘main-sidebar’.$i,