Cannot configure `select_additional` thru registry.

[maethu]

Goto Plone Setup --> registry --> search for "select_additional" --> click on the link to configure.

The following error appears.

Module ZPublisher.Publish, line 138, in publish
Module ZPublisher.mapply, line 77, in mapply
Module ZPublisher.Publish, line 48, in call_object
Module plone.z3cform.layout, line 66, in __call__
Module plone.z3cform.layout, line 50, in update
Module plone.app.registry.browser.edit, line 28, in update
Module z3c.form.form, line 226, in update
Module plone.z3cform.patch, line 21, in BaseForm_update
Module z3c.form.form, line 154, in update
Module z3c.form.form, line 136, in updateWidgets
Module z3c.form.field, line 257, in update
Module zope.component._api, line 107, in getMultiAdapter
Module zope.component._api, line 120, in queryMultiAdapter
Module zope.component.registry, line 238, in queryMultiAdapter
Module zope.interface.adapter, line 532, in queryMultiAdapter
Module z3c.form.browser.orderedselect, line 90, in SequenceSelectFieldWidget
Module zope.component._api, line 109, in getMultiAdapter
ComponentLookupError: ((<plone.registry.field.Tuple object at 0x7f847fabdb18>, None, <HTTPRequest, URL=https://stadtwerk-backend.winterthur.ch/portal_registry/edit/ftw.referencewidget.interfaces.IReferenceSettings.select_additional>), <InterfaceClass z3c.form.interfaces.IFieldWidget>, u'')