A WooCommerce checkout 500 error is different from an individual payment refusal. It usually means the checkout path hit a server-side failure, a fatal PHP error, an Ajax endpoint problem, a gateway initialization break or a plugin conflict before the order could be completed.
The customer may only see a spinning checkout, a white screen, a generic internal server error or a place-order button that never completes. The store can still look online while revenue is blocked at the exact step where orders are supposed to happen.
Signals that point to a technical checkout error
Look for the earliest step where the failure appears. Common signals include a checkout page returning 500, `update_order_review` failing, a Store API or Ajax response returning an error, payment methods disappearing after the form refreshes, or the page turning blank after the customer clicks place order.
CashFlowCanary treats those signals as a conversion incident rather than a generic uptime event. The useful proof is the affected step, expected signal, observed failure class, timestamp and priority, not a dump of customer data.
What to distinguish from a normal payment refusal
A normal refusal affects one payment attempt. A technical checkout error affects the checkout capability itself: payment methods fail to load, the order cannot be created, the confirmation page is never reached, or the same failure appears repeatedly on a controlled journey.
This distinction matters for triage. A card refusal usually belongs to payment support. A checkout 500 error, fatal error, Ajax failure or white screen belongs to the technical team or agency responsible for the WooCommerce stack.
Useful proof for a developer or agency
Useful proof should answer four questions: which step broke, what was expected, what was observed and why it matters now. It should avoid secrets, customer names, email addresses, cart contents and raw screenshots that may expose personal data.
If you need a broader diagnostic path, start with the broken checkout pillar. For payment-specific failures, compare with WooCommerce payment failed. To see how incidents become shareable evidence, open the incident example. To frame a first site, request a free audit or compare the plans.
Monitoring this class of failure
Monitoring should not stop at the checkout URL returning 200. It should follow the revenue path far enough to detect whether cart, checkout, payment and confirmation signals still behave as expected.
When a technical error is detected, CashFlowCanary keeps the incident open until checks return green. That gives merchants and agencies a concise record of the break, the recovery signal and the proof to share without exposing unnecessary customer data.