Fatal error: Uncaught Error: Call to a member function addLink() on null in /home/vkart2016/public_html/app/code/community/IWD/Opc/Block/Links.php:17 Stack trace: #0 /home/vkart2016/public_html/app/code/local/Smartwave/All/Model/Core/Layout.php(141): IWD_Opc_Block_Links->addCheckoutLink() #1 /home/vkart2016/public_html/app/code/local/Smartwave/All/Model/Core/Layout.php(79): Smartwave_All_Model_Core_Layout->_runAction(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element)) #2 /home/vkart2016/public_html/app/code/core/Mage/Core/Model/Layout.php(214): Smartwave_All_Model_Core_Layout->_generateAction(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element)) #3 /home/vkart2016/public_html/app/code/local/Smartwave/All/Model/Core/Layout.php(31): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element)) #4 /home/vkart2016/public_html/app/code/core/Mage/Core/Model/Layout.php(206): Smartwave_All_Model_Core_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element in /home/vkart2016/public_html/app/code/community/IWD/Opc/Block/Links.php on line 17