webcouturier.dropdownmenu in Plone 5 - drop-down-menu

Question

I've installed webcouturier.dropdownmenu in Plone 5.0.4
I followed instructions in:
http://quintagroup.com/services/support/tutorials/textnroll-theme/textnroll-plone5/drop-down
It works, but I got an error when I click in Setup, Add-on... like this:
Traceback (innermost last):
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.z3cform.fieldsets.extensible, line 59, in update
Module plone.z3cform.patch, line 30, in GroupForm_update
Module z3c.form.group, line 132, in update
Module z3c.form.form, line 136, in updateWidgets
Module z3c.form.field, line 277, in update
Module z3c.form.browser.select, line 51, in update
Module z3c.form.browser.widget, line 171, in update
Module z3c.form.widget, line 233, in update
Module z3c.form.widget, line 227, in updateTerms
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.term, line 104, in ChoiceTerms
Module zope.schema._field, line 312, in bind
Module Zope2.App.schema, line 32, in get
Module zope.component._api, line 169, in getUtility
ComponentLookupError: (<InterfaceClass zope.schema.interfaces.IVocabularyFactory>, 'plone.app.vocabularies.ImagesScales')
How can I fix this ?
Thanks!

Answer 1

Upgrade to Plone 5.0.5.
For some reason,that specific vocabulary was dropped in later versions of plone.app.vocabularies 2.x, (Probably used from Plone 5.0.2 to 5.0.4), which is why the quintagroup instructions warn against 5.0.2. I guess it was written when 5.0.2 was the newest version.
From 5.0.5, Plone uses plone.app.vocabularies 3.x, which restores that vocabulary.
You could try to just upgrade plone.app.vocabularies, but it's probably easier to just upgrade the Plone instance as a whole.