How to fix "Invalid block type:" issue on Magento 1.9

Question

First off, I have tried many other SE users' answers but to no avail. As you will see in my code below; the issue is that my exceptions.log file is throwing this back at me:

Mage_Core_Model_Layout->addBlock('', '')

which does not really help. I have even tried turning on DB query logs (please see: https://firebearstudio.com/blog/the-complete-guide-to-magento-debugging.html) to try find the issue but also nothing.

Does anyone else have any suggestions to try find the bloody blocks causing the issues.

Many thanks in advance.

2019-08-12T11:38:21+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/Helper/Product/View.php(73): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/Helper/Product/View.php(144): Mage_Catalog_Helper_Product_View->initProductLayout(Object(Anowave_Ec_Model_Product), Object(Mage_Catalog_ProductController))
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/ProductController.php(132): Mage_Catalog_Helper_Product_View->prepareAndRender(1239, Object(Mage_Catalog_ProductController), Object(Varien_Object))
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_ProductController->viewAction()
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#12 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#13 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#14 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#15 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#16 {main}


2019-08-12T11:38:32+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}


2019-08-12T11:42:24+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}


2019-08-12T11:43:59+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}
2019-08-12T11:44:14+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}


2019-08-12T11:44:35+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}


2019-08-12T11:44:36+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}
2019-08-12T11:44:37+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: ' in /var/www/vhosts/example.com/htdocs/app/Mage.php:595
Stack trace:
#0 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('', Array)
#2 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('', '')
#3 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('', '')
#4 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(205): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /var/www/vhosts/example.com/htdocs/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#12 /var/www/vhosts/example.com/htdocs/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#13 /var/www/vhosts/example.com/htdocs/index.php(88): Mage::run('', 'store')
#14 {main}