Contribution plugin -- falty instructions?

On “contribution types” tab, Display Name box, it says:


but if that is blank and save changes is pressed, an error message is output. (below)
I’d like to use the metadata associated with all the “item types” already established, on the contribution page/form. The instructions, as I understand them, infer that if the Display Name is blank it will use the existing “item types”. If not, do I have to reconstruct all the item types metadata for the Contribution form?? Thanks!
Omeka V2.7.1, Contribution V3.2.

Zend_Db_Statement_Mysqli_Exception: Mysqli statement execute error : Column ‘display_name’ cannot be null in /home/letterst/public_html/lw/application/libraries/Zend/Db/Statement/Mysqli.php:214
Stack trace:
#0 /home/letterst/public_html/lw/application/libraries/Zend/Db/Statement.php(303): Zend_Db_Statement_Mysqli->_execute(Array)
#1 /home/letterst/public_html/lw/application/libraries/Zend/Db/Adapter/Abstract.php(480): Zend_Db_Statement->execute(Array)
#2 /home/letterst/public_html/lw/application/libraries/Omeka/Db.php(80): Zend_Db_Adapter_Abstract->query(‘INSERT INTO `om…’, Array)
#3 /home/letterst/public_html/lw/application/libraries/Omeka/Db.php(257): Omeka_Db->__call(‘query’, Array)
#4 /home/letterst/public_html/lw/application/libraries/Omeka/Record/AbstractRecord.php(541): Omeka_Db->insert(‘omkkw_contribut…’, Array)
#5 /home/letterst/public_html/lw/plugins/Contribution/controllers/TypesController.php(126): Omeka_Record_AbstractRecord->save()
#6 /home/letterst/public_html/lw/plugins/Contribution/controllers/TypesController.php(32): Contribution_TypesController->_processForm(Object(ContributionType))
#7 /home/letterst/public_html/lw/application/libraries/Zend/Controller/Action.php(516): Contribution_TypesController->editAction()
#8 /home/letterst/public_html/lw/application/libraries/Zend/Controller/Dispatcher/Standard.php(308): Zend_Controller_Action->dispatch(‘editAction’)
#9 /home/letterst/public_html/lw/application/libraries/Zend/Controller/Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http))
#10 /home/letterst/public_html/lw/application/libraries/Zend/Application/Bootstrap/Bootstrap.php(105): Zend_Controller_Front->dispatch()
#11 /home/letterst/public_html/lw/application/libraries/Zend/Application.php(384): Zend_Application_Bootstrap_Bootstrap->run()
#12 /home/letterst/public_html/lw/application/libraries/Omeka/Application.php(73): Zend_Application->run()
#13 /home/letterst/public_html/lw/admin/index.php(28): Omeka_Application->run()
#14 {main}