Call to a member function getSource() on a non-object (boolean)

#0 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/community/Creare/CreareSeoCore/Helper/Data.php(13): Mage_Catalog_Model_Product->getAttributeText()
#1 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/community/Creare/CreareSeoCore/Model/Observer.php(98): Creare_CreareSeoCore_Helper_Data->getDiscontinuedProductUrl()
#2 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Model/App.php(1339): Creare_CreareSeoCore_Model_Observer->discontinuedCheck()
#3 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Model/App.php(1318): Mage_Core_Model_App->_callObserverMethod()
#4 /home/goodstore/domains/www.goodstore.nl/public_html/app/Mage.php(449): Mage_Core_Model_App->dispatchEvent()
#5 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(561): Mage::dispatchEvent()
#6 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(419): Mage_Core_Controller_Varien_Action->norouteAction()
#7 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch()
#8 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(176): Mage_Core_Controller_Varien_Router_Standard->match()
#9 /home/goodstore/domains/www.goodstore.nl/public_html/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#10 /home/goodstore/domains/www.goodstore.nl/public_html/app/Mage.php(685): Mage_Core_Model_App->run()
#11 /home/goodstore/domains/www.goodstore.nl/public_html/index.php(91): Mage::run()
#12 {main}