SSL

Your SSL certificate expired, or the visitor’s clock is wrong. Confirm which with one command, renew the certificate, and fix the DNS, CAA or blocked-challenge problem that stopped it renewing.

You enter the right password and land back on wp-login.php, or see “Cookies are blocked”. Trace the auth cookies, then fix URL, HTTPS proxy, cache and session problems.

Your certificate is valid but was issued for a different name. Learn how to read the SAN list, fix www and subdomain gaps, and stop the server sending the wrong certificate.

Your certificate works but the padlock is missing or parts of the page fail to load. Find every http:// reference and fix it at the source, including builder data.

The TLS handshake fails before any certificate check. Find out whether port 443 speaks HTTP, has no certificate, or offers no shared TLS version or cipher.

HSTS removes the “proceed anyway” link, so any certificate fault locks visitors out. Learn how the header works, how to clear it for testing, and how to roll it out safely.

Works in your browser but fails on Android, curl or an API client? The server is probably missing its intermediate certificate. Learn to test and fix the chain.

Four versions of your address should reach one canonical URL in a single redirect. Test all four, set WordPress to match, then write one combined rule at the server or CDN.

A subdomain needs three things: a DNS record, a server that knows the name, and a certificate that covers it. Test each one separately and the broken link shows itself.

Your free certificate will not issue or renew. Read the validation error, then fix DNS, the Cloudflare proxy, blocked .well-known paths, CAA records, port 80 or rate limits.