One of my clients websites also had a fatal crash . Deactivating the plugin helped.
This is from error log:
require_once(/xxxxx/public_html/wp-content/plugins/sche…………e/xxxx/public_html/wp-includes/class-wp-hook.php(348): WP_Hook->apply_filters()\n#3 /home/xxxxx/public_html/wp-includes/plug…’,