Hi,
The latest Yoast 3.2.4 version together with WP 4.5.1 breaks the admin. For various actions - e.g. previewing a post or saving a draft - a white screen is the result.
Basically most of WP admin features don't work and Chrome console shows a 500 error for loading admin-ajax.php.
Disabling Yoast SEO (premium) immediately fixes this.
Cheers,
Thomas