What causes "Invalid language code" in apache/superset?

Use a supported language code (e.g., en, fr, zh) as defined in LANGUAGES.

Invalid language code

Error message

Invalid language code

What it means

Error "Invalid language code" thrown in apache/superset.

Source

Thrown at superset/views/core.py:695

        """
        datasource_id, datasource_type = request.args["datasourceKey"].split("__")
        datasource = DatasourceDAO.get_datasource(
            DatasourceType(datasource_type), int(datasource_id)
        )
        # Check if datasource exists
        if not datasource:
            return json_error_response(DATASOURCE_MISSING_ERR)

        datasource.raise_for_access()
        return json_success(json.dumps(sanitize_datasource_data(datasource.data)))

    @event_logger.log_this
    @has_access
    @expose("/language_pack/<lang>/")
    def language_pack(self, lang: str) -> FlaskResponse:
        # Only allow expected language formats like "en", "pt_BR", etc.
        if not LANGUAGE_CODE_RE.match(lang):
            abort(400, "Invalid language code")

        base_dir = os.path.join(os.path.dirname(__file__), "..", "translations")
        file_path = safe_join(base_dir, lang, "LC_MESSAGES", "messages.json")

        if file_path and os.path.isfile(file_path):
            return send_file(file_path, mimetype="application/json")

        return json_error_response(
            "Language pack doesn't exist on the server", status=404
        )

    @expose("/language_pack/<lang>/<version>/script.js")
    def language_pack_script(self, lang: str, version: str) -> FlaskResponse:
        """Serve the language pack as a content-addressed classic script.

        spa.html loads this BEFORE the entry bundle so translations are
        configured synchronously (no race with code-split chunks), while the
        versioned URL lets browsers cache the pack as immutable and pick up a

View on GitHub (pinned to f4587218dd)

Solutions

Use a supported language code (e.g., en, fr, zh) as defined in LANGUAGES.

When it happens

Trigger: A request carries an unrecognized language code.

Common situations: Posting a language pack whose language code is not a valid/known code.

AI-assisted analysis of apache/superset@f4587218dd (2026-08-14). Data as JSON: /api/errors/8bf1f3cf6396e963. Report an issue: GitHub.