apache/superset · error · ValidationError

Not a valid YAML file

Error message

Not a valid YAML file

What it means

Error "Not a valid YAML file" thrown in apache/superset.

Source

Thrown at superset/commands/importers/v1/utils.py:64

    """Remove the first directory of a path"""
    full_path = PurePosixPath(file_path)
    relative_path = PurePosixPath(*full_path.parts[1:])
    return str(relative_path)


class MetadataSchema(Schema):
    version = fields.String(required=True, validate=validate.Equal(IMPORT_VERSION))
    type = fields.String(required=False)
    timestamp = fields.DateTime()


def load_yaml(file_name: str, content: str) -> dict[str, Any]:
    """Try to load a YAML file"""
    try:
        return yaml.safe_load(content)
    except yaml.YAMLError as ex:
        logger.exception("Invalid YAML in %s", file_name)
        raise ValidationError({file_name: "Not a valid YAML file"}) from ex


def load_metadata(contents: dict[str, str]) -> dict[str, str]:
    """Apply validation and load a metadata file"""
    if METADATA_FILE_NAME not in contents:
        # if the contents have no METADATA_FILE_NAME this is probably
        # a original export without versioning that should not be
        # handled by this command
        raise IncorrectVersionError(f"Missing {METADATA_FILE_NAME}")

    metadata = load_yaml(METADATA_FILE_NAME, contents[METADATA_FILE_NAME])
    try:
        MetadataSchema().load(metadata)
    except ValidationError as ex:
        # if the version doesn't match raise an exception so that the
        # dispatcher can try a different command version
        if "version" in ex.messages:
            raise IncorrectVersionError(ex.messages["version"][0]) from ex

View on GitHub (pinned to f4587218dd)

Solutions

1. Ensure the file is valid YAML with a .yaml/.yml extension.
2. Validate the YAML syntax with a linter before uploading.

When it happens

Trigger: An uploaded import file cannot be parsed as YAML.

Common situations: Importing assets from an uploaded file whose contents are not parseable YAML.

AI-assisted analysis of apache/superset@f4587218dd (2026-08-14). Data as JSON: /api/errors/e36f28c5195aa92e. Report an issue: GitHub.