order details are not displayed in admin dashboard - Magento 1.9.1

After SUPEE-7405 patch Sales Order Management screen in Magento Backend is blank or the following error is reported in PHP error log:

PHP Parse error: syntax error, unexpected '[' in app/code/core/Mage/Adminhtml/Helper/Sales.php on line 124

SUPEE-7405 is prepared with PHP 5.4 in mind, older PHP versions are incompatible with new language constructions used.

Solution

Change line 124 in app/code/core/Mage/Adminhtml/Helper/Sales.php 

from $links = []; 

to 

$links = array();