The new Site Health feature is one of the best things to be added to WordPress for a long time.
It gives administrators:
updates recommendations – for both the server (PHP version and HTTPS) and WordPress
maintenance recommendations (e.g. remove inactive plugins and themes)
configuration and health checks (e.g. background update checks working)
a place to view, copy, and share important debug information
It can be accessed from the wp-admin in the Tools -> Site Health menu.
PHP fatal recovery (WSOD protection)
Previous to WordPress 5.2 – when WordPress experienced a fatal error it would stop working – showing what was known as the “white screen of death” (WSOD).
WordPress 5.2 changes how this happens – instead front end users will see an error message which reads
The site is experiencing technical difficulties.
and the site administrator will receive an email notifying of the error and include a special link to access the wp-admin in “recovery mode”. This allows the site administrator to safely fix or manage fatal errors without needing access to the server.