i had yoast Seo installed and it seem to work fine then i followed the setup here http://www.wpbeginner.com/plugins/how-to-install-and-setup-wordpress-seo-plugin-by-yoast/
and after the setup i got White page on my whole site except admin.
when deactivate yoast Seo i get the site back. i have also deleted yoast plugin and installed again but every time i activate i get white page.
warm regards Kimberley