Critical error when updated

After updating I got a critical error and an email saying “WordPress caught an error with one of your plugins, Yoast SEO.”

The issue affects a page in the WP back end. I cannot view the live traffic page on my Wordfence plugin. Get an critical error page.

My host has been unable to solve it.

I have rolled back to an earlier version of my database; deactivated the plugin, and then deleted it; changed the theme. Nothing has worked.

Any ideas? I am completely at sea.

—–

WordPress version 5.4
Current theme: Kreativ Pro (version 1.2.2)
Current plugin: Yoast SEO (version 14.0.1)
PHP version 7.1.21

Error Details
=============
An error of type E_ERROR was caused in line 30 of the file /var/sites/n/n*****.com/public_html/wp-content/plugins/wordpress-seo/vendor/composer/autoload_real.php. Error message: Uncaught Error: Class ‘Composer\Autoload\ComposerStaticInit42746c705929ac3daf11c1ac3d85c7c4’ not found in /var/sites/n/n*****.com/public_html/wp-content/plugins/wordpress-seo/vendor/composer/autoload_real.php:30
Stack trace:
#0 /var/sites/n/n*****.com/public_html/wp-content/plugins/wordpress-seo/vendor/autoload.php(7): ComposerAutoloaderInit42746c705929ac3daf11c1ac3d85c7c4::getLoader()
#1 /var/sites/n/n*****.com/public_html/wp-content/plugins/wordpress-seo/wp-seo-main.php(71): require(‘/var/sites/n/na…’)
#2 /var/sites/n/n*****.com/public_html/wp-content/plugins/wordpress-seo/wp-seo.php(48): require_once(‘/var/sites/n/na…’)
#3 /var/sites/n/n*****.com/public_html/wp-settings.php(377): include_once(‘/var/sites/n/na…’)
#4 /var/sites/n/n*****.com/public_html/wp-config.php(76): require_once(‘/var/sites/n/na…’)
#5 /var/sites/n/n*****.com/public_html/wp-load.php(37): require_once(‘/var/sites/n/na…’)
#6 /var/sites/n/n*****.com/public_html/wp-admin/admin