Notice: Array to string conversion  in /var/www/schatkaartprod/app/code/core/Mage/Core/Model/Layout.php on line 555

#0 /var/www/schatkaartprod/app/code/core/Mage/Core/Model/Layout.php(555): mageCoreErrorHandler(8, 'Array to string conversion', '/var/www/schatkaartprod/app/code/core/Mage/Core/Model/Layout.php', 555, Array)
#1 /var/www/schatkaartprod/app/code/core/Mage/Core/Controller/Varien/Action.php(390): Mage_Core_Model_Layout->getOutput()
#2 /var/www/schatkaartprod/app/code/core/Mage/Customer/controllers/AccountController.php(131): Mage_Core_Controller_Varien_Action->renderLayout()
#3 /var/www/schatkaartprod/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Customer_AccountController->loginAction()
#4 /var/www/schatkaartprod/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('login')
#5 /var/www/schatkaartprod/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Mage_Core_Controller_Request_Http)
#6 /var/www/schatkaartprod/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#7 /var/www/schatkaartprod/app/Mage.php(683): Mage_Core_Model_App->run(Array)
#8 /var/www/schatkaartprod/index.php(87): Mage->run('', 'store')