Magento – Magento 2 Recaptcha Uncaught TypeError: Cannot read property ‘nodeName’ of undefined

You need to add a translated string (or both) in the Magecomp Recaptcha Module translation file (should be app/locale/[your_LANG]/Magecomp_Recaptcha.csv) if there is one.

The translated string to add to the translation file for the italian language could be:

"Please click on the reCAPTCHA box.123","Si prega di cliccare sul reCAPTCHA box.123"
"Please click on the reCAPTCHA box.456","Si prega di cliccare sul reCAPTCHA box.456"

Then you have to edit the code in this way:

public function Customercreate($observer)
{

    try {

        if (Mage::helper('recaptcha/data')->showOnRegister()) {
             $g_response = Mage::app()->getRequest()->getParam('g-recaptcha-response');
            if (isset($g_response) && !empty($g_response)):
                if (!(Mage::helper('recaptcha')->Validate_captcha($g_response))):

                    Mage::getSingleton('core/session')->addError(Mage::helper('recaptcha/data')->__('Please click on the reCAPTCHA box.123'));

                    $url = Mage::helper('core/http')->getHttpReferer() ? Mage::helper('core/http')->getHttpReferer() : Mage::getUrl();
                    Mage::app()->getFrontController()->getResponse()->setRedirect($url);
                    Mage::app()->getResponse()->sendResponse();
                    exit;
                endif;
            else:
                $observer->getEvent()->setData(null);

                Mage::getSingleton('core/session')->addError(Mage::helper('recaptcha/data')->__('Please click on the reCAPTCHA box.456'));

                $url = Mage::helper('core/http')->getHttpReferer() ? Mage::helper('core/http')->getHttpReferer() : Mage::getUrl();
                Mage::app()->getFrontController()->getResponse()->setRedirect($url);
                Mage::app()->getResponse()->sendResponse();
                exit;
            endif;
        }
    } catch (Exception $e) {
        Mage::log("Captcha Error :" . $e->getMessage(), null, "recaptcha.log");
    }
}

---

I don't know the Magecomp_Recaptcha Module, but this module to supports translations need to setup a .csv translation file in the app/code/local/Magecomp/Recaptcha/etc/config.xml: look for the config/frontend/translate tag in this file. If there is no translation file setup, you need to add it:

<?xml version="1.0"?>
<config>
    [...]
    <frontend>
        <translate>
            <modules>
                <Magecomp_Recaptcha>
                    <files>
                        <default>Magecomp_Recaptcha.csv</default>
                    </files>
                </Magecomp_Recaptcha>
            </modules>
        </translate>
    </frontend>
    [...]
</config>

Then add the 2 rows below to your app/locale/[your_LANG]/Magecomp_Recaptcha.csv file.

Do not load ReCaptcha block if disabled

In /vendor/msp/recaptcha/Block/Frontend/ReCaptcha.php

=> replace this code in ReCaptcha.php

<?php
/**
 * MageSpecialist
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to info@magespecialist.it so we can send you a copy immediately.
 *
 * @category   MSP
 * @package    MSP_ReCaptcha
 * @copyright  Copyright (c) 2017 Skeeller srl (http://www.magespecialist.it)
 * @license    http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

namespace MSP\ReCaptcha\Block\Frontend;

use Magento\Framework\App\ObjectManager;
use Magento\Framework\View\Element\Template;
use MSP\ReCaptcha\Model\Config;
use MSP\ReCaptcha\Model\LayoutSettings;
use Zend\Json\Json;

class ReCaptcha extends Template
{
    /**
     * @var Config
     */
    private $config;

    /**
     * @var LayoutSettings
     */
    private $layoutSettings;

    /**
     * @param Template\Context $context
     * @param null $decoder @deprecated
     * @param null $encoder @deprecated
     * @param LayoutSettings $layoutSettings
     * @param array $data
     * @param Config|null $config
     */
    public function __construct(
        Template\Context $context,
        $decoder,
        $encoder,
        LayoutSettings $layoutSettings,
        array $data = [],
        Config $config = null
    ) {
        parent::__construct($context, $data);
        $this->layoutSettings = $layoutSettings;
        $this->config = $config ?: ObjectManager::getInstance()->get(Config::class);
    }

    /**
     * Get public reCaptcha key
     * @return string
     */
    public function getPublicKey()
    {
        return $this->config->getPublicKey();
    }

    /**
     * Get current recaptcha ID
     */
    public function getRecaptchaId()
    {
        return (string) $this->getData('recaptcha_id') ?: 'msp-recaptcha-' . md5($this->getNameInLayout());
    }

    /**
     * @inheritdoc
     */
    public function getJsLayout()
    {
        $layout = Json::decode(parent::getJsLayout(), Json::TYPE_ARRAY);

        if ($this->config->isEnabledFrontend()) {
            // Backward compatibility with fixed scope name
            if (isset($layout['components']['msp-recaptcha'])) {
                $layout['components'][$this->getRecaptchaId()] = $layout['components']['msp-recaptcha'];
                unset($layout['components']['msp-recaptcha']);
            }

            $recaptchaComponentSettings = [];
            if (isset($layout['components'][$this->getRecaptchaId()]['settings'])) {
                $recaptchaComponentSettings = $layout['components'][$this->getRecaptchaId()]['settings'];
            }
            $layout['components'][$this->getRecaptchaId()]['settings'] = array_replace_recursive(
                $this->layoutSettings->getCaptchaSettings(),
                $recaptchaComponentSettings
            );

            $layout['components'][$this->getRecaptchaId()]['reCaptchaId'] = $this->getRecaptchaId();
        }

        return Json::encode($layout);
    }

    /**
     * @return string
     */
    public function toHtml()
    {
        if (!$this->config->isEnabledFrontend()) {
            return '';
        }
        return parent::toHtml();
    }

}