I would like to report a bug.

The CMS pages import contains an invalid (nonexisting block)

exception 'Mage_Core_Exception' with message 'Invalid block type: Mage_Newsletterpopup_Block_Subscribe' in /src/ac/app/Mage.php:595
Stack trace:
#0 /src/ac/app/code/core/Mage/Core/Model/Layout.php(495): Mage::throwException('Invalid block t...')
#1 /src/ac/app/code/core/Mage/Core/Model/Layout.php(437): Mage_Core_Model_Layout->_getBlockInstance('newsletterpopup...', Array)
#2 /src/ac/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('newsletterpopup...', 'newsletterpopup')
#3 /src/ac/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('newsletterpopup...', 'newsletterpopup')
#4 /src/ac/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 /src/ac/app/code/core/Mage/Core/Model/Layout.php(210): Mage_Core_Model_Layout->generateBlocks(Object(Mage_Core_Model_Layout_Element))
#6 /src/ac/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#7 /src/ac/app/code/core/Mage/Cms/Helper/Page.php(113): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /src/ac/app/code/core/Mage/Cms/Helper/Page.php(52): Mage_Cms_Helper_Page->_renderPage(Object(Mage_Cms_IndexController), 'home')
#9 /src/ac/app/code/core/Mage/Cms/controllers/IndexController.php(45): Mage_Cms_Helper_Page->renderPage(Object(Mage_Cms_IndexController), 'home')
#10 /src/ac/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Cms_IndexController->indexAction()
#11 /src/ac/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('index')
#12 /src/ac/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#13 /src/ac/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#14 /src/ac/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#15 /src/ac/index.php(77): Mage::run('default', 'store')
#16 {main}

Patch file with fix attached.

Patch to fix: