Zend certified PHP/Magento developer

Registry Error while Migrate magento 1.9.4.3 instance from local to server

I have uploaded my magento fresh setup to server and I am getting registry error like this

On front side

There has been an error processing your request
Mage registry key "_singleton/megamenu/observer" already exists

Trace:
#0 /home/*****/public_html/app/Mage.php(226): Mage::throwException('Mage registry k...')
#1 /home/*****/public_html/app/Mage.php(480): Mage::register('_singleton/mega...', false)
#2 /home/*****/public_html/app/code/core/Mage/Core/Model/App.php(1352): Mage::getSingleton('megamenu/observ...')
#3 /home/*****/public_html/app/Mage.php(451): Mage_Core_Model_App->dispatchEvent('core_layout_blo...', Array)
#4 /home/*****/public_html/app/code/core/Mage/Core/Model/Layout.php(459): Mage::dispatchEvent('core_layout_blo...', Array)
#5 /home/*****/public_html/app/code/core/Mage/Core/Model/Layout.php(472): Mage_Core_Model_Layout->createBlock('page/html', 'root')
#6 /home/*****/public_html/app/code/core/Mage/Core/Model/Layout.php(239): Mage_Core_Model_Layout->addBlock('page/html', 'root')
#7 /home/*****/public_html/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))
#8 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(344): Mage_Core_Model_Layout->generateBlocks()
#9 /home/*****/public_html/app/code/core/Mage/Cms/Helper/Page.php(113): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#10 /home/*****/public_html/app/code/core/Mage/Cms/Helper/Page.php(52): Mage_Cms_Helper_Page->_renderPage(Object(Mage_Cms_IndexController), 'home')
#11 /home/*****/public_html/app/code/core/Mage/Cms/controllers/IndexController.php(45): Mage_Cms_Helper_Page->renderPage(Object(Mage_Cms_IndexController), 'home')
#12 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Cms_IndexController->indexAction()
#13 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('index')
#14 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#15 /home/*****/public_html/app/code/core/Mage/Core/Model/App.php(381): Mage_Core_Controller_Varien_Front->dispatch()
#16 /home/*****/public_html/app/Mage.php(687): Mage_Core_Model_App->run(Array)
#17 /home/*****/public_html/index.php(83): Mage::run('', 'store')
#18 {main}

Om admin side

Mage registry key "_singleton/blog/observer" already exists

Trace:
#0 /home/*****/public_html/app/Mage.php(226): Mage::throwException('Mage registry k...')
#1 /home/*****/public_html/app/Mage.php(480): Mage::register('_singleton/blog...', false)
#2 /home/*****/public_html/app/code/core/Mage/Core/Model/App.php(1352): Mage::getSingleton('blog/observer')
#3 /home/*****/public_html/app/Mage.php(451): Mage_Core_Model_App->dispatchEvent('controller_acti...', Array)
#4 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(527): Mage::dispatchEvent('controller_acti...', Array)
#5 /home/*****/public_html/app/code/core/Mage/Adminhtml/Controller/Action.php(167): Mage_Core_Controller_Varien_Action->preDispatch()
#6 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(407): Mage_Adminhtml_Controller_Action->preDispatch()
#7 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('login')
#8 /home/*****/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#9 /home/*****/public_html/app/code/core/Mage/Core/Model/App.php(381): Mage_Core_Controller_Varien_Front->dispatch()
#10 /home/*****/public_html/app/Mage.php(687): Mage_Core_Model_App->run(Array)
#11 /home/*****/public_html/index.php(83): Mage::run('', 'store')
#12 {main}

Does anyone know how to get out of this?