JS error with exit notifier

We get this error below when clicking links when your plugin is enabled, and your plugin does not work:

frontend.js?ver=1.4.3:4 Uncaught TypeError: Cannot read property ‘length’ of undefined
at HTMLDocument.exit_notifier_leave_now (frontend.js?ver=1.4.3:4)
at HTMLDocument.dispatch (jquery.js?ver=1.12.4:3)
at HTMLDocument.r.handle (jquery.js?ver=1.12.4:3)

Have disabled it in the meantime

We have PHP7 installed.

Here are all the plugins installed (its not Autoptimize or WP Rocket as I tested it with those disabled):

+———————————————-+———-+———–+———+
| name | status | update | version |
+———————————————-+———-+———–+———+
| acf-content-analysis-for-yoast-seo | active | none | 2.0.1 |
| aryo-activity-log | active | none | 2.4.1 |
| codepress-admin-columns | active | none | 3.1.10 |
| advanced-custom-fields-pro | active | none | 5.6.10 |
| advanced-woo-search | active | none | 1.41 |
| malinky-ajax-pagination | active | none | 2.0.1 |
| akismet | active | none | 4.0.3 |
| autoptimize | active | none | 2.3.4 |
| backupbuddy | active | available | 8.1.0.1 |
| taxonomy-terms-order | active | none | 1.5.3.2 |
| contact-form-7 | active | none | 5.0.2 |
| contact-form-7-infusionsoft-add-on | active | none | 1.2.2 |
| uk-cookie-consent | active | none | 2.3.10 |
| duplicate-post | active | none | 3.2.2 |
| eventbrite-api | active | none | 1.0.12 |
| exit-notifier | inactive | none | 1.4.3 |
| fg-magento-to-woocommerce-premium | active | none | 2.38.0 |
| gift-aid-for-woocommerce | active | none | 1.3.5 |
| give | active | none | 2.1.2 |
| give-email-reports | active | none | 1.1.1 |
| give-gift-aid | active | none | 1.1.2 |
| give-paypal-pro | active | none | 1.1.5 |
| give-stripe | active | none | 2.0.3 |
| google-analytics-for-wordpress | active | none | 7.0.6 |
| gravityforms | active | none | 2.3.2 |
| infusionsoft | active | none | 1.5.12 |
| iwp-client | active | none | 1.8.1 |
| better-wp-security | active | none | 6.9.2 |
| jetpack | active | none | 6.1.1 |
| keyring | active | none | 1.9 |
| mailchimp-for-wp | active | none | 4.2.2 |
| mc4wp-premium | active | none | 3.1.5 |
| optinmonster | active | none | 1.3.5 |
| php-code-widget | active | none | 2.3 |
| ppress | active | none | 1.5.3 |
| really-simple-captcha | active | none | 2.0.1 |
| redirection | active | none | 3.2 |
| regenerate-thumbnails | active | none | 3.0.2 |
| relevanssi | active | none | 4.0.9 |
| search-exclude | active | none | 1.2.2 |
| searchwp | active | available | 2.8.15 |
| searchwp-term-synonyms | active | available | 2.4.11 |
| searchwp-woocommerce | active | available | 1.1.17 |
| shortcode-ui | active | none | 0.7.3 |
| sql-executioner | active | none | 1.4 |
| tinymce-advanced | active | none | 4.7.11 |
| user-switching | active | none | 1.3.0 |
| woocommerce | active | available | 3.3.5 |
| woocommerce_donations_on_cart | active | none | 1.91 |
| woocommerce-gateway-stripe | active | none | 4.1.4 |
| woocommerce-table-rate-shipping | active | none | 3.0.7 |
| wordfence | active | none | 7.1.6 |
| wordpress-importer | active | none | 0.6.4 |
| wp-optimize | active | none | 2.2.4 |
| wp-all-export | active | none | 1.2.0 |
| wp-all-import | active | none | 3.4.8 |
| wp-migrate-db | active | none | 1.0.2 |
| wp-rocket | active | none | 3.0.4 |
| wp-store-locator | active | none | 2.2.14 |
| yith-woocommerce-ajax-product-filter-premium | active | available | 3.4.7 |
| wordpress-seo | active | none | 7.5.1 |
| wp-migrate-db-pro-compatibility | must-use | none | 1.1 |
| advanced-cache.php | dropin | none | |
+———————————————-+———-+———–+———+

P.S. I think your http://cvstech.com/ site was hacked. It redirected me to a page with popups, and now gives a 500 error.