Topic
Fixes for the errors that take a WordPress site down.
Troubleshooting
WordPress checked a capability and the account did not have it. After a migration the usual reason is not the role at all — it is that the table prefix changed and the row describing the account's role no longer matches.
Troubleshooting
The number is specific and useful: 28 is always a timeout, never a refusal or a certificate problem. What matters next is which request timed out, because a loopback to your own site and a call to a payment provider need opposite fixes.
Troubleshooting
The installer refused because a directory with that name is already there, usually left by an install that failed partway. The folder is the evidence, and deleting the wrong one removes a working plugin.
Troubleshooting
The editor asked the REST API for JSON and got something else back. Whatever that something is — an HTML error page, a redirect, or a stray warning — is the actual fault, and it is visible in one browser tab.
Troubleshooting
The message is deliberately vague because it is shown to visitors. The actual error is in the log, and recovery mode will email you the file and line that failed.
Troubleshooting
A blank screen, an endless spinner, or a page that will not save almost always traces back to a blocked REST API request or a JavaScript error. Work through causes in order of likelihood rather than guessing.
Troubleshooting
Removing malware is the easy half. The half people skip is proving it is gone, and every scanner type is blind to something the others catch.
Website Tools
Putting a proxy in front of WordPress solves real problems and introduces a specific set of new ones — redirect loops, mixed content, cached logged-in pages and a visitor IP that is no longer the visitor.
WooCommerce
Filters fail in three distinct ways: nothing happens, everything disappears, or the results are wrong. Each points at a different layer — the query, the attribute data, or a cache serving a filtered page to everybody.
WooCommerce
Free shipping is a method inside a zone, gated by a requirement. When it does not appear, the customer's address matched a different zone, the minimum was calculated on a different total, or a cached session is holding an old rate.
WooCommerce
Endpoints like /my-account/orders/ are not real pages — they are rewrite rules on top of one page. When they 404 or render blank, the cause is the rewrite table, a missing shortcode or block, or a page assignment.
Troubleshooting
When a site works everywhere except one browser, the site is usually fine. Prove where the fault lives with four tests, then fix the extension, the cache, the certificate or the CSS that only that browser cares about.