Omeka has encountered an error

BadMethodCallException

Method named 'fetchOrderedItems' does not exist or is not callable.

exception 'BadMethodCallException' with message 'Method named 'fetchOrderedItems' does not exist or is not callable.' in /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Omeka/Db/Table.php:83
Stack trace:
#0 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/themes/EHCdefault/items/show.php(57): Omeka_Db_Table->__call('fetchOrderedIte...', Array)
#1 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/themes/EHCdefault/items/show.php(57): Omeka_Db_Table->fetchOrderedItems(1)
#2 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Omeka/View.php(117): include('/home/edmyc058/...')
#3 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/View/Abstract.php(888): Omeka_View->_run('/home/edmyc058/...')
#4 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(912): Zend_View_Abstract->render('items/show.php')
#5 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(933): Zend_Controller_Action_Helper_ViewRenderer->renderScript('items/show.php', NULL)
#6 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Action/Helper/ViewRenderer.php(972): Zend_Controller_Action_Helper_ViewRenderer->render()
#7 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Action/HelperBroker.php(277): Zend_Controller_Action_Helper_ViewRenderer->postDispatch()
#8 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Action.php(527): Zend_Controller_Action_HelperBroker->notifyPostDispatch()
#9 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('showAction')
#10 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#11 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#12 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Zend/Application.php(384): Zend_Application_Bootstrap_Bootstrap->run()
#13 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/application/libraries/Omeka/Application.php(77): Zend_Application->run()
#14 /home/edmyc058/public_html/eastbourneheritagecentre.co.uk/index.php(23): Omeka_Application->run()
#15 {main}