Syntax error, parse error, unexpected

Hello

I am getting the following message:

Parse error: syntax error, unexpected 'yield' (T_YIELD) in /home2/angelsc4/public_html/admin/bonfire/themes/default/index.php on line 8

the code is
<?php echo theme_view('parts/_header'); ?>


<div class="container body narrow-body"> <!-- Start of Main Container -->

<?php

    echo Template::message();
    echo isset($content) ? $content : Template::yield();
?>

<?php echo theme_view('parts/_footer'); ?>






can anyone suggest how to resolve this problem