Fatal error:

I don’t need to use MailPoet anymore and want to remove it from my website. But, when deactivated or deleted I get this message on my WP site and it also messes up other plugins.:

Fatal error: Uncaught Error: Class ‘MailPoet\Form\Widget’ not found in /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-content/themes/read-child/footer-2.php:25 Stack trace: #0 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-includes/template.php(810): require_once() #1 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-includes/template.php(745): load_template(‘/hermes/bosnacw…’, true, Array) #2 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-includes/general-template.php(92): locate_template(Array, true, true, Array) #3 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-content/themes/read-child/page-home.php(44): get_footer(‘2’) #4 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-includes/template-loader.php(106): include(‘/hermes/bosnacw…’) #5 /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-blog-header.php(19): require_once(‘/hermes/bosnacw…’) #6 in /hermes/bosnacweb08/bosnacweb08au/b2166/d5.eliotrbrown/public_html/wp/wp-content/themes/read-child/footer-2.php on line 25
There has been a critical error on this website.

What do I do? This error only goes away when MailPoet is activated but I don’t want MailPoet.

The page I need help with: [log in to see the link]