Its happened to all of us. You purchase a plugin or download one for free from the WordPress repository, install it on your site, and either the plugin doesn’t work or it messes something up on your site.
Mark Hess from 'MarketingInUnderware' has published a great solution to this problem.
You can read the article and watch the video here:
https://marketinginunderwear.com/blog/new-plugin-installed-not-working/