After version 5.4, things have improved regarding language mapping problems.
Some codes are still not managed. In the cases encountered, frm (Medieval French) and fro (Old French).
Would it be possible to include all codes in the Dataverse source?

What steps does it take to reproduce the issue?
Try to harvest from https://repository.ortolang.fr/api/oai/?verb=ListRecords&set=producer:atilf&metadataPrefix=oai_dc
6 datasets are not harvested, 4 due to language mapping issues.

What happens?
Mapping errrors documented in the harvest log :
Exception processing getRecord(), oaiUrl=https://repository.ortolang.fr/api/oai, identifier=oai:ortolang.fr:0c2017f1-7c3b-473a-b75d-ad97b4e09bd0, edu.harvard.iq.dataverse.api.imports.ImportException, Failed to import harvested dataset: class edu.harvard.iq.dataverse.util.json.ControlledVocabularyException (Value 'fro' does not exist in type 'language')"
I'm attaching the server.log relevant extract and the harvest log.

harvest_ortolang3_2022-04-04T15-34-00.log
server.log

Which version of Dataverse are you using?
5.10

Any related open or closed issues to this bug report?

• Harvesting client fails : Zenodo "Couperin" community / error with "language" field mapping. #7638