No content on admin pages

Your admin is suddenly showing admin pages without content, but not a real white screen of death, like this:

Possible cause

Yoast SEO uses a function called bccomp(). bccomp() is a function of the PHP Library BCMath, which is bundled with PHP since PHP 4.0.4. We recently discovered that BCMath is not configured with PHP on a very small number of hosts. In those cases your WP admin will look like the screenshot above when it encounters the bccomp() function.

Best solution

The best solution is to contact your web host and ask them to configure PHP with BCMath on your server. Since BCMath is bundled with PHP, they won’t have to add new packages or download anything. Just configuring PHP with --enable-bcmath will solve the issue immediately.