Перенес ветку cache в config/global. Ошибка изменилась, но осталась:
Notice: unserialize(): Error at offset 0 of 349 bytes in /var/www/magento/lib/Zend/Cache/Backend/TwoLevels.php on line 234
#0 [internal function]: mageCoreErrorHandler(8, 'unserialize(): ...', '/var/www/magent...', 234, Array)
#1 /var/www/magento/lib/Zend/Cache/Backend/TwoLevels.php(234): unserialize('{"seo":[true,tr...')
#2 /var/www/magento/lib/Zend/Cache/Core.php(306): Zend_Cache_Backend_TwoLevels->load('e84_DF_LICENSOR...', false)
#3 /var/www/magento/lib/Varien/Cache/Core.php(158): Zend_Cache_Core->load('DF_LICENSOR_MOD...', false, false)
#4 /var/www/magento/app/code/core/Mage/Core/Model/Cache.php(379): Varien_Cache_Core->load('DF_LICENSOR_MOD...')
#5 /var/www/magento/app/code/local/Df/Core/Model/Abstract.php(667): Mage_Core_Model_Cache->load('Df_Licensor_Mod...')
#6 /var/www/magento/app/code/local/Df/Core/Model/Abstract.php(654): Df_Core_Model_Abstract->cacheLoadProperty('_enabled', 'Df_Licensor_Mod...')
#7 /var/www/magento/app/code/local/Df/Core/Model/Abstract.php(626): Df_Core_Model_Abstract->cacheLoadArea(Array, 'Df_Licensor_Mod...')
#8 /var/www/magento/app/code/local/Df/Core/Model/Abstract.php(823): Df_Core_Model_Abstract->cacheLoad()
#9 /var/www/magento/app/code/local/Varien/Object.php(85): Df_Core_Model_Abstract->_construct()
#10 /var/www/magento/app/code/local/Df/Licensor/Model/CachedSingleton.php(60): Varien_Object->__construct()
#11 /var/www/magento/app/code/local/Df/Core/lib/fp/licensor.php(35): Df_Licensor_Model_CachedSingleton::s()
#12 /var/www/magento/app/code/local/Df/Core/Model/Url/Rewrite.php(15): df_enabled('seo')
#13 /var/www/magento/app/code/core/Mage/Core/Model/Url/Rewrite/Request.php(139): Df_Core_Model_Url_Rewrite->loadByRequestPath(Array)
#14 /var/www/magento/app/code/core/Mage/Core/Model/Url/Rewrite/Request.php(116): Mage_Core_Model_Url_Rewrite_Request->_rewriteDb()
#15 /var/www/magento/app/code/core/Mage/Core/Controller/Varien/Front.php(165): Mage_Core_Model_Url_Rewrite_Request->rewrite()
#16 /var/www/magento/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#17 /var/www/magento/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#18 /var/www/magento/index.php(87): Mage::run('', 'store')
#19 {main}