Site doesn't load correctly

Hi, excuse my english.

The plugin installs correctly. But basic settings makes the site load in a wrong way. It crashed the theme slideshow, for example.

Even basic settings like Load CSS and JS asynchronously makes the site load incomplete.

Thanks in advance.

https://wordpress.org/plugins/async-js-and-css/