Omeka has encountered an error

Zend_Form_Exception

Method setSubmitButtonText does not exist

#0 /websites/omekadev/home/www/aha14demo/plugins/GuestUser/controllers/UserController.php(32): Zend_Form->__call('setSubmitButton...', Array)
#1 /websites/omekadev/home/www/aha14demo/plugins/GuestUser/controllers/UserController.php(32): Omeka_Form_User->setSubmitButtonText('Register')
#2 /websites/omekadev/home/www/aha14demo/application/libraries/Zend/Controller/Action.php(516): GuestUser_UserController->registerAction()
#3 /websites/omekadev/home/www/aha14demo/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('registerAction')
#4 /websites/omekadev/home/www/aha14demo/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#5 /websites/omekadev/home/www/aha14demo/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(101): Zend_Controller_Front->dispatch()
#6 /websites/omekadev/home/www/aha14demo/application/libraries/Zend/Application.php(366): Zend_Application_Bootstrap_Bootstrap->run()
#7 /websites/omekadev/home/www/aha14demo/application/libraries/Omeka/Application.php(79): Zend_Application->run()
#8 /websites/omekadev/home/www/aha14demo/index.php(23): Omeka_Application->run()
#9 {main}