Traceback (innermost last):
  Module ZPublisher.Publish, line 119, in publish
  Module ZPublisher.mapply, line 88, in mapply
  Module ZPublisher.Publish, line 42, in call_object
  Module zope.formlib.form, line 769, in __call__
  Module Products.Five.formlib.formbase, line 55, in update
  Module zope.formlib.form, line 732, in update
  Module plone.fieldsets.form, line 30, in setUpWidgets
  Module zope.formlib.form, line 379, in setUpEditWidgets
  Module zope.schema._field, line 354, in bind
  Module zope.schema._field, line 243, in bind
  Module zope.app.schema.vocabulary, line 34, in get
  Module plone.app.vocabularies.workflow, line 34, in __call__
  Module zope.i18n, line 110, in translate
  Module Products.PlacelessTranslationService.utility, line 23, in translate
AttributeError: __contains__