Hello.
I have also the same error. This is the message I see in the dashboard.
Warning! WP Super Cache caching broken! The script advanced-cache.php could not load wp-cache-phase1.php.
Please edit /homepages/9/d429818722/htdocs/wp-content/advanced-cache.php and make sure the path to /homepages/9/d429818722/htdocs/wp-content/plugins/wp-super-cache/wp-cache-phase1.php is correct.
Can anyone help? Thanks.