GeoNetwork 4.0.4 release is a minor release with some changes:
Search results / Improve performance with overview as dataURL
Editor / List format as protocols
Editor / Fix compute extents from keywords
Filestore / Jcloud implementation
INSPIRE / Validation / Remove internal schematron. Use INSPIRE validator instead.
DOI / Improve Datacite conversion
Security / Password enforcement
Index health check improvements
Add proxy for microservice eg. OGC API Records
and more … see 4.0.4 issues and
pull requests for full details.