Invalid HTTP response code

#0 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/lib/Zend/Controller/Response/Abstract.php(150): Zend_Controller_Response_Abstract->setHttpResponseCode(10)
#1 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Controller/Response/Http.php(107): Zend_Controller_Response_Abstract->setRedirect('http://www.buil...', 10)
#2 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/local/Mirasvit/Seo/Model/Observer.php(441): Mage_Core_Controller_Response_Http->setRedirect('http://www.buil...', 10)
#3 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/local/Mirasvit/Seo/Model/Observer.php(345): Mirasvit_Seo_Model_Observer->redirect('http://www.buil...', '10')
#4 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/local/Mirasvit/Seo/Model/Observer.php(264): Mirasvit_Seo_Model_Observer->_redirectFromRedirectManagerUrlList()
#5 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Model/App.php(1358): Mirasvit_Seo_Model_Observer->checkUrl(Object(Varien_Event_Observer))
#6 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Model/App.php(1337): Mage_Core_Model_App->_callObserverMethod(Object(Mirasvit_Seo_Model_Observer), 'checkUrl', Object(Varien_Event_Observer))
#7 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_acti...', Array)
#8 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Controller/Varien/Action.php(527): Mage::dispatchEvent('controller_acti...', Array)
#9 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Controller/Front/Action.php(69): Mage_Core_Controller_Varien_Action->preDispatch()
#10 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Controller/Varien/Action.php(407): Mage_Core_Controller_Front_Action->preDispatch()
#11 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#12 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/local/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#13 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#14 /var/www/vhosts/builderdepot.co.uk/httpdocs/releases/20170804125557/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#15 /nfs/825452-NFSClus1.builderdepot.co.uk/builderdepot.co.uk_shared/index.php(125): Mage::run('default', 'store')
#16 {main}