https://bugzilla.wikimedia.org/show_bug.cgi?id=66619
--- Comment #10 from xqt info@gno.de --- In past we had a structure like the following for the error:
{u'error': {u'code': u'failed-save', u'info': u'Another item (Q1151870) already has label "disambiguation" and description "Wikimedia disambiguation page" associated with language code en.', u'messages': {u'0': {u'name': u'wikibase-error-label-not-unique-item', u'parameters': [u'disambiguation', u'en', {}, u'Wikimedia disambiguation page'], u'type': u'error'}, u'html': {u'*': u'<p>Another item (Q1151870) already has label "disambiguation" and description "Wikimedia disambiguation page" associated with language code en.\n</p>'}}}, u'servedby': u'mw1199'}
now result['error']['messages']['0']['name'] does not work anymore to get the u'wikibase-error-label-not-unique-item',