Omeka has encountered an error

Omeka_View_Exception

A current item variable has not been set to this view.

exception 'Omeka_View_Exception' with message 'A current item variable has not been set to this view.' in /usr/local/data/htdocs/omeka/application/views/helpers/GetCurrentRecord.php:27
Stack trace:
#0 [internal function]: Omeka_View_Helper_GetCurrentRecord->getCurrentRecord('item', true)
#1 /usr/local/data/htdocs/omeka/application/libraries/Zend/View/Abstract.php(350): call_user_func_array(Array, Array)
#2 /usr/local/data/htdocs/omeka/application/libraries/globals.php(1825): Zend_View_Abstract->__call('getCurrentRecor...', Array)
#3 /usr/local/data/htdocs/omeka/application/libraries/globals.php(1825): Omeka_View->getCurrentRecord('item', true)
#4 /usr/local/data/htdocs/omeka/plugins/BookReader/helpers/BookReaderFunctions.php(151): get_current_record('item')
#5 /usr/local/data/htdocs/omeka/plugins/BookReader/controllers/IndexController.php(83): BookReader::sendImage(NULL, NULL)
#6 /usr/local/data/htdocs/omeka/application/libraries/Zend/Controller/Action.php(516): BookReader_IndexController->imageProxyAction()
#7 /usr/local/data/htdocs/omeka/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('imageProxyActio...')
#8 /usr/local/data/htdocs/omeka/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#9 /usr/local/data/htdocs/omeka/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#10 /usr/local/data/htdocs/omeka/application/libraries/Zend/Application.php(382): Zend_Application_Bootstrap_Bootstrap->run()
#11 /usr/local/data/htdocs/omeka/application/libraries/Omeka/Application.php(79): Zend_Application->run()
#12 /usr/local/data/htdocs/omeka/index.php(23): Omeka_Application->run()
#13 {main}