Invalid block type error

Question

I'm attempting to override the core navigation module in Magento with my plugin however, it is not working as it should. The plugin runs however an error is thrown.

2015-01-19T06:43:13+00:00 ERR (3): 
exception 'Mage_Core_Exception' with message 'Invalid block type: VNav_Catalog_Block_Navigation' in C:\wamp\www\magento\app\Mage.php:595
Stack trace:
#0 C:\wamp\www\magento\includes\src\__default.php(28016): Mage::throwException('Invalid block t...')
#1 C:\wamp\www\magento\includes\src\__default.php(27958): Mage_Core_Model_Layout->_getBlockInstance('catalog/navigat...', Array)
#2 C:\wamp\www\magento\includes\src\__default.php(27993): Mage_Core_Model_Layout->createBlock('catalog/navigat...', 'catalog.leftnav')
#3 C:\wamp\www\magento\includes\src\__default.php(27760): Mage_Core_Model_Layout->addBlock('catalog/navigat...', 'catalog.leftnav')
#4 C:\wamp\www\magento\includes\src\__default.php(27726): Mage_Core_Model_Layout->_generateBlock(Object(Mage_Core_Model_Layout_Element), Object(Mage_Core_Model_Layout_Element))
#5 C:\wamp\www\magento\includes\src\__default.php(27731): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 C:\wamp\www\magento\includes\src\__default.php(13941): Mage_Core_Model_Layout->generateBlocks()
#7 C:\wamp\www\magento\app\code\core\Mage\Catalog\controllers\CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 C:\wamp\www\magento\includes\src\__default.php(14015): Mage_Catalog_CategoryController->viewAction()
#9 C:\wamp\www\magento\includes\src\__default.php(18399): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 C:\wamp\www\magento\includes\src\__default.php(17933): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 C:\wamp\www\magento\includes\src\__default.php(20705): Mage_Core_Controller_Varien_Front->dispatch()
#12 C:\wamp\www\magento\app\Mage.php(684): Mage_Core_Model_App->run(Array)
#13 C:\wamp\www\magento\index.php(85): Mage::run('', 'store')
#14 {main}

Plugins files:

C:\wamp\www\magento\app\code\local\VNav\Catalog\etc\config.xml

<?xml version="1.0"?>
<config>
<modules>
    <VNav_Catalog>
        <version>0.1.0</version>
    </VNav_Catalog>
</modules>

<global>
    <blocks>
        <catalog>
            <rewrite>
                <navigation>VNav_Catalog_Block_Navigation</navigation>
            </rewrite>
        </catalog>
    </blocks>
</global>
</config>

C:\wamp\www\magento\app\code\local\VNav\Catalog\Block\Navigation.php:

class VNav_Catalog_Block_Navigation extends Mage_Catalog_Block_Navigation{}

C:\wamp\www\magento\app\etc\modules\VNav_Catalog.xml:

<?xml version="1.0"?>
<config>
<modules>
    <VNav_Catalog>
        <active>true</active>
        <codePool>local</codePool>
        <depends />
    </VNav_Catalog>
</modules>
</config>

Any ideas why? Thanks!

Answer 1

Your rewrite code seems to be ok. From your screen shot I can see that magento compilation has been enabled within your system. Please disable compilation within admin>System>Tool>Compilation and after that enable compilation again.