Wordpress Plugin - CSS not loading

Question

Plugins are not loading the CSS files.

The CSS of the theme is loading just fine but the plugin CSS does not load.

^{If relevant, the website is: http://de.rundertisch.org/}

Answer 1

wp_head(); was missing from header.php before

also don't forget wp_footer(); in footer.php before

Answer 2

I had a similar problem where the style did load but wasn't working correctly. I solved it by replacing:

<body>

with

<body <?php body_class(); ?>>