Specific user unable to edit or delete pages in select exhibits

One Super User is unable to delete or rearrange the order of exhibit pages in 4 particular exhibits but has no problem with the rest. Several of us have tried and failed to reproduce the error with those exhibits. The Super User has tried multiple browsers and both Windows and Mac OS. The site is running Omeka 2.3

The error message:
2016-07-25T13:06:58-05:00 ERR (3): exception 'Omeka_Validate_Exception' with message 'Slug: This page slug has already been used.  Please modify the slug so that it is unique.' in /var/www/Omeka/application/libraries/Omeka/Record/AbstractRecord.php:535
Stack trace:
#0 /var/www/Omeka/plugins/ExhibitBuilder/models/Exhibit.php(245): Omeka_Record_AbstractRecord->save()
#1 /var/www/Omeka/plugins/ExhibitBuilder/models/Exhibit.php(201): Exhibit->_savePages(Array)
#2 [internal function]: Exhibit->afterSave(Array)
#3 /var/www/Omeka/application/libraries/Omeka/Record/AbstractRecord.php(277): call_user_func(Array, Array)
#4 /var/www/Omeka/application/libraries/Omeka/Record/AbstractRecord.php(550): Omeka_Record_AbstractRecord->runCallbacks('afterSave', Array)
#5 /var/www/Omeka/application/libraries/Omeka/Controller/AbstractActionController.php(229): Omeka_Record_AbstractRecord->save(false)
#6 /var/www/Omeka/application/libraries/Zend/Controller/Action.php(516): Omeka_Controller_AbstractActionController->editAction()
#7 /var/www/Omeka/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch('editAction')
#8 /var/www/Omeka/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#9 /var/www/Omeka/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#10 /var/www/Omeka/application/libraries/Zend/Application.php(382): Zend_Application_Bootstrap_Bootstrap->run()
#11 /var/www/Omeka/application/libraries/Omeka/Application.php(79): Zend_Application->run()
#12 /var/www/Omeka/admin/index.php(28): Omeka_Application->run()
#13 {main}

You said the Omeka version is 2.3, but what version is the Exhibit Builder plugin?

Exhibit Builder is 3.3

Thanks.

I can’t think of a situation where one user would hit this problem alone and it wouldn’t affect other users equally. You can get a slug-related error like this if you’re trying to move pages around such that two pages with the same slug end up as siblings. Maybe this one user is just making different moves that cause slug conflicts while the others aren’t?

Ah, thanks I’ll look into it from that angle.