The facet does not exist

Error: The requested address '/documents/facets?amp%253BclearFacets=1&amp%253BnewFacet=subjectFacet%253Dfran%25C3%25A7ais+langue+%25C3%25A9trang%25C3%25A8re&newFacet=dateFacet%253D1985' was not found on this server.