Magento Fatal error: Call to a member function is Shipping Labels Available() on a non-object

When I click the Ship button, I get this error in the lower right corner, where there should be a button:

Fatal error: Call to a member function isShippingLabelsAvailable() on a non-object in /var/www/limp/app/code/core/Mage/Adminhtml/Block/Sales/Order/Shipment/Create/Items.php on line 132

Here i got solution for it just replace text shown in below.

change line 1214 of app/code/core/Mage/Sales/Model/Order.php from

$shippingMethod = parent::getShippingMethod(); 

to

$shippingMethod = $this->getData('shipping_method'); 

I hope this work for you.