class InvalidSettings(Exception):
    status_code = 400

    def __init__(self, message, status_code=None, payload=None):
        super(InvalidSettings, self).__init__()
        self.message = message
        if status_code is not None:
            self.status_code = status_code
        self.payload = payload

    def to_dict(self):
        rv = dict(self.payload or ())
        rv['message'] = self.message
        return rv

@app.errorhandler(InvalidSettings)
def handle_invalid_settings(error):
    response = json.dumps(error.to_dict())
    response.status_code = error.status_code
    return response

TypeError: __init__() got an unexpected keyword argument 'errors'