Error when creating Shipping Method

When trying to create a Shipping Method I get a white screen, I’ve been following through the shop setup instructions and everything else so far has worked.

The PHP error is:

[13-Jul-2016 11:38:05 Europe/London] PHP Fatal error:  Call to a member function index() on null in /Users/twolittlefishes/Sites/amgscripts.co.uk/perch/addons/apps/perch_shop/modes/shipping.edit.pre.php on line 45

My diagnostic report is:

Perch: 2.8.31, PHP: 5.6.10, MySQL: mysqlnd 5.0.11-dev - 20120503 - $Id: 3c688b6bbc30d36af3ac34fdd4b7b5b787fe5555 $, with PDO
Server OS: Darwin, cgi-fcgi
Installed apps: content (2.8.31), assets (2.8.31), categories (2.8.31), perch_forms (1.8.3), perch_shop_orders (1.0.6), perch_shop_products (1.0.6), perch_shop (1.0.6), perch_members (1.5)
App runtimes: <?php $apps_list = array( 'content', 'categories', 'perch_forms', 'perch_members', 'perch_shop', );
PERCH_LOGINPATH: /perch
PERCH_PATH: /Users/twolittlefishes/Sites/amgscripts.co.uk/perch
PERCH_CORE: /Users/twolittlefishes/Sites/amgscripts.co.uk/perch/core
PERCH_RESFILEPATH: /Users/twolittlefishes/Sites/amgscripts.co.uk/perch/resources
Image manipulation: GD
PHP limits: Max upload 32M, Max POST 32M, Memory: 128M, Total max file upload: 32M
F1: 2edba60ed1f613d6dd804feb202456a2
Resource folder writeable: Yes
SCRIPT_NAME: /perch/core/settings/diagnostics/index.php
REQUEST_URI: /perch/core/settings/diagnostics/
DOCUMENT_ROOT: /Users/twolittlefishes/Sites/amgscripts.co.uk
HTTP_HOST: amgscripts.local