Hello there,
Thank you for creating a topic.
We just investigated your problem and found that you get JavaScript error from Revolution Slider and it comes from conflict of this plugin and CMB2
We also found similar known issue on Yoast SEO github https://github.com/Yoast/wordpress-seo/issues/4453
Since it doesn’t come from our theme we can’t provide you a proper fix for that. But as a workaround you just remove the line from the file wp-content/plugins/revslider/includes/tinybox.class.php
$plugin_array['revslider_sc_button'] = RS_PLUGIN_URL . 'admin/assets/js/tinymce-shortcode-script.js';
Regards