}
            } catch (final Exception e) {
                logger.warn("Failed to process a request.", e);
                throwValidationError(messages -> messages.addErrorsDesignFileNameIsInvalid("designFile"), this::asListHtml);
            }
        }
        if (StringUtil.isBlank(fileName)) {

     * message: The file name is invalid.
     * </pre>
     * @param property The property name for the message. (NotNull)
     * @return this. (NotNull)
     */
    public FessMessages addErrorsDesignFileNameIsInvalid(String property) {
        assertPropertyNotNull(property);
        add(property, new UserMessage(ERRORS_design_file_name_is_invalid));
        return this;
    }

    /**