it crushed the website

it crushed the website right after installing the plugin. by the way i am already using Gravity Form plugin and wanted to install this Add-on. which i did and it crushed the whole website and giving me 500 Error page. which is sucks since its our production website and live on the web. so i had to quickly login to FTP and to delete the plugin manually, since it was not opening WP admin pages or any other page.