try {
            if (UPLOAD.equals(form.id)) {
                if (form.jarFile == null) {
                    throwValidationError(messages -> messages.addErrorsPluginFileIsNotFound(GLOBAL, form.id), this::asListHtml);
                }
                if (!form.jarFile.getFileName().endsWith(".jar")) {

     * @param property The property name for the message. (NotNull)
     * @param arg0 The parameter arg0 for message. (NotNull)
     * @return this. (NotNull)
     */
    public FessMessages addErrorsPluginFileIsNotFound(String property, String arg0) {
        assertPropertyNotNull(property);
        add(property, new UserMessage(ERRORS_plugin_file_is_not_found, arg0));
        return this;
    }

    /**