An error of type E_ERROR was caused in line 77

When the plugin is activated and you try to edit a post the site hits a critical error. Only way to edit the post is disable the plugin. Error message rec’d below:

WordPress version 5.4.2
Current theme: Child (version 1.0.0)
Current plugin: Schema Markup Rich Snippets (version 1.0.3)
PHP version 7.4.7

Error Details
=============
An error of type E_ERROR was caused in line 77 of the file /home/REDACTED/public_html/wp-content/plugins/schema-markup-rich-snippets/includes/admin/metabox/class-metabox.php. Error message: Uncaught Error: Class ‘CMB2_Hookup’ not found in /home/REDACTED/public_html/wp-content/plugins/schema-markup-rich-snippets/includes/admin/metabox/class-metabox.php:77
Stack trace:
#0 /home/REDACTED/public_html/wp-includes/class-wp-hook.php(287): RANKMATH_SCHEMA\Admin\Metabox\Metabox->enqueue(‘post.php’)
#1 /home/REDACTED/public_html/wp-includes/class-wp-hook.php(311): WP_Hook->apply_filters(NULL, Array)
#2 /home/REDACTED/public_html/wp-includes/plugin.php(478): WP_Hook->do_action(Array)
#3 /home/REDACTED/public_html/wp-admin/admin-header.php(104): do_action(‘admin_enqueue_s…’, ‘post.php’)
#4 /home/REDACTED/public_html/wp-admin/edit-form-advanced.php(419): require_once(‘/home/REDACTED…’)
#5 /home/REDACTED/public_html/wp-admin/post.php(206): require(‘/home/REDACTED…’)
#6 {main}
thrown

Please help.