Smartcrawl slows down site

Once I enable Smartcrawl in my site it becomes extremely slow, Hummingbird can't do performance tests and Google page speed can't scan the site too.

Based on host provider feedback, seems Smartcrawl is currently attempting to access the following repeatedly and failing each time: public_html/wp-content/plugins/wpmu-dev-seo/class-mappings.php because of this, it gets stuck in an infinite loop.