When a user edits content, a new version with a version status INTERNAL_DRAFT (5) is created. If the REST API is then used to query for the versions of that object, the result is a HTTP 500, "Undefined version status: 5".

This happens because the Repository loads all versions including internal ones, the controller does not filter the result, and \eZ\Publish\Core\REST\Server\Output\ValueObjectVisitor\VersionInfo reacts to all statuses except DRAFT, PUBLISHED and ARCHIVED with an Exception.