What it is

Your site's PHP memory limit is lower than the recommended minimum for a modern WordPress install (256MB). Plugin-heavy sites — page builders, WooCommerce, security plugins, often several running together — routinely exhaust a low limit and crash with a white-screen or "allowed memory size exhausted" fatal error.

How to fix it

Raise the PHP memory limit (wp-config.php, .user.ini, php.ini or .htaccess, whichever your host allows) to at least 256MB. If you're not sure how, install the WordPress Plugin: its Security tab applies fixes like this one automatically.