Method "onCoreLayoutBlockCreateAfter" is not defined in "Amasty_Orderattr_Model_Observer"

#0 /home/purefit/public_html/shop-online/includes/src/__default.php(21823): Mage::throwException('Method "onCoreL...')
#1 /home/purefit/public_html/shop-online/includes/src/__default.php(21800): Mage_Core_Model_App->_callObserverMethod(Object(Amasty_Orderattr_Model_Observer), 'onCoreLayoutBlo...', Object(Varien_Event_Observer))
#2 /home/purefit/public_html/shop-online/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('core_layout_blo...', Array)
#3 /home/purefit/public_html/shop-online/includes/src/__default.php(28211): Mage::dispatchEvent('core_layout_blo...', Array)
#4 /home/purefit/public_html/shop-online/includes/src/__default.php(28224): Mage_Core_Model_Layout->createBlock('core/template', 'formkey')
#5 /home/purefit/public_html/shop-online/includes/src/__default.php(27991): Mage_Core_Model_Layout->addBlock('core/template', 'formkey')
#6 /home/purefit/public_html/shop-online/includes/src/__default.php(27957): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#7 /home/purefit/public_html/shop-online/includes/src/__default.php(14024): Mage_Core_Model_Layout->generateBlocks()
#8 /home/purefit/public_html/shop-online/includes/src/__default.php(11397): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#9 /home/purefit/public_html/shop-online/includes/src/__default.php(11336): Mage_Cms_Helper_Page->_renderPage(Object(Mage_Cms_IndexController), 'home')
#10 /home/purefit/public_html/shop-online/app/code/core/Mage/Cms/controllers/IndexController.php(45): Mage_Cms_Helper_Page->renderPage(Object(Mage_Cms_IndexController), 'home')
#11 /home/purefit/public_html/shop-online/includes/src/__default.php(14098): Mage_Cms_IndexController->indexAction()
#12 /home/purefit/public_html/shop-online/includes/src/__default.php(18511): Mage_Core_Controller_Varien_Action->dispatch('index')
#13 /home/purefit/public_html/shop-online/includes/src/__default.php(18045): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#14 /home/purefit/public_html/shop-online/includes/src/__default.php(20837): Mage_Core_Controller_Varien_Front->dispatch()
#15 /home/purefit/public_html/shop-online/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#16 /home/purefit/public_html/shop-online/index.php(88): Mage::run('', 'store')
#17 {main}