Fatal PHP error protection
WordPress 5.2 includes protection for fatal errors in PHP code, when a fatal error is detected by WordPress then the user will see a WordPress error message instead of a “white screen of death”. An email is also sent to the administrator of the site.
Recovery mode means that plugins and/or themes which might be causing the fatal error are not executed any more, in order for an administrator to fix the problem and still access the backend as usual.
The theme or plugin causing the problem can be deactivated as usual, which makes it possible to have an at least semi-functional site while the problem is being fixed. Once the problem is fixed, the theme or plugin can be activated again.
PHP 5.6.2 is the minimum required version to run WordPress 5.2 on
The minimum required version is now 5.6.2 under WordPress 5.2, we highly recommend using a higher version than that though, since versions 5.6 and 7.0 are not receiving anymore security updates. If you are running an outdated version of PHP then we recommend that you update as soon as possible, preferably on a staging version of the site.
Additions to the Site Health Check functionality
The Site Health Check feature was added in WordPress 5.1 in order to alert users of outdated versions of PHP, this is extended in WordPress 5.2 by adding two new pages to help debug common WordPress issues. The Site Health pages can be found under Tools->Site Health in the WordPress menu.
New body tag hook
wp_body_open hook was included in WordPress 5.2, which lets developers inject code just after the opening