Neos\Flow\Mvc\Controller\ActionController::getFlattenedValidationErrorMessage PHP Method

    protected function getFlattenedValidationErrorMessage()
    {
        $outputMessage = 'Validation failed while trying to call ' . get_class($this) . '->' . $this->actionMethodName . '().' . PHP_EOL;
        $logMessage = $outputMessage;
        foreach ($this->arguments->getValidationResults()->getFlattenedErrors() as $propertyPath => $errors) {
            foreach ($errors as $error) {
                $logMessage .= 'Error for ' . $propertyPath . ':  ' . $error->render() . PHP_EOL;
            }
        }
        $this->systemLogger->log($logMessage, LOG_ERR);
        return $outputMessage;
    }