Checks

After an update, each key page is compared with its baseline. A finding is a failure or a warning.

Code	Level	Meaning
fatal	Failure	A PHP fatal error the page did not have before
critical_error	Failure	WordPress’s “critical error” screen
status_degraded	Failure	The page used to return 2xx or 3xx and now returns 4xx or 5xx
transport_failed	Failure	The page did not respond
probe_error	Failure	The page could not be checked cleanly
page_missing	Failure	A page checked before was not checked after
marker_missing	Failure	Text you said the page must contain is gone
marker_forbidden	Failure	Text you said the page must never contain is there
landmark_lost	Failure	An important part of the layout is gone, such as the main content area or the WooCommerce cart or checkout form
raw_shortcode	Failure	A shortcode now shows as plain text
asset_404	Failure	The page links to a script or stylesheet on your site that is now missing
php_warning	Warning	New PHP warnings or deprecations
log_lines	Warning	New lines in the PHP error log during the update
structure_changed	Warning	The layout is less similar to the baseline than your structure threshold
unverified	Warning	Something could not be checked, such as a logged-in page without the probe user, or a page left unchecked because the check ran out of time

A check that runs out of time (120 seconds by default) is unverified and never causes a restore. A failure that the baseline already had on the same page is not blamed on the update.

Checks make loopback requests to your own site. They read page output only. Page bodies are not stored, and they are not returned to the screens or to agents.