I'm using paypal express check out.In order review if i click place order button i'm getting this error. I don't have idea why this error coming.Any one can give some idea to resolve this issue.
a:4:{i:0;s:53:"Mage registry key "application_params" already exists";i:1;s:2487:"#0 /home/bd/public_html/staging/app/Mage.php(222): Mage::throwException('Mage registry k...')
#1 /home/bd/public_html/staging/app/code/core/Mage/Core/Model/App.php(338): Mage::register('application_par...', Array)
#2 /home/bd/public_html/staging/app/Mage.php(683): Mage_Core_Model_App->run(Array)
#3 /home/bd/public_html/staging/app/code/core/Mage/Sales/Model/Order/Item.php(98): Mage::run('', 'store')
#4 /home/bd/public_html/staging/lib/Varien/Autoload.php(96): include('/home/bd/...')
#5 [internal function]: Varien_Autoload->autoload('Mage_Sales_Mode...')
#6 [internal function]: spl_autoload_call('Mage_Sales_Mode...')
#7 /home/bd/public_html/staging/app/code/core/Mage/Core/Model/Config.php(1346): class_exists('Mage_Sales_Mode...')
#8 /home/bd/public_html/staging/app/Mage.php(462): Mage_Core_Model_Config->getModelInstance('sales/order_ite...', Array)
#9 /home/bd/public_html/staging/app/code/core/Mage/Sales/Model/Convert/Quote.php(128): Mage::getModel('sales/order_ite...')
#10 /home/bd/public_html/staging/app/code/core/Mage/Sales/Model/Service/Quote.php(170): Mage_Sales_Model_Convert_Quote->itemToOrderItem(Object(Mage_Sales_Model_Quote_Item))
#11 /home/bd/public_html/staging/app/code/core/Mage/Sales/Model/Service/Quote.php(249): Mage_Sales_Model_Service_Quote->submitOrder()
#12 /home/bd/public_html/staging/app/code/core/Mage/Paypal/Model/Express/Checkout.php(560): Mage_Sales_Model_Service_Quote->submitAll()
#13 /home/bd/public_html/staging/app/code/core/Mage/Paypal/Controller/Express/Abstract.php(320): Mage_Paypal_Model_Express_Checkout->place('EC-5R2755885S34...')
#14 /home/bd/public_html/staging/app/code/core/Mage/Core/Controller/Varien/Action.php(419): Mage_Paypal_Controller_Express_Abstract->placeOrderAction()
#15 /home/bd/public_html/staging/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(250): Mage_Core_Controller_Varien_Action->dispatch('placeOrder')
#16 /home/bd/public_html/staging/app/code/core/Mage/Core/Controller/Varien/Front.php(176): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#17 /home/bd/public_html/staging/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#18 /home/bd/public_html/staging/app/Mage.php(683): Mage_Core_Model_App->run(Array)
#19 /home/bd/public_html/staging/index.php(97): Mage::run('', 'store')
#20 {main}";s:3:"url";s:29:"/paypaluk/express/placeOrder/";s:11:"script_name";s:10:"/index.php";}