415 Unsupported Media Type means the server refused the request because the format of the request body is not supported. In most cases, the URL is correct and the server is reachable, but the body format, Content-Type, Content-Encoding, or upload type does not match what the endpoint expects. This is a request-format problem, not a … Read more
405 Method Not Allowed means the server understands the HTTP method, but the specific resource you requested does not allow that method. In simple terms, the URL exists, the server knows what GET, POST, PUT, or DELETE means, but that endpoint is not configured to accept the method you used. This is a configuration or … Read more
Cloudflare Origin Server Refused Connection usually means Cloudflare reached your origin server, but the origin refused the connection instead of accepting it. In most real cases, this maps to Cloudflare Error 521. This is not the same as a DNS problem or a timeout. The domain may resolve correctly, and Cloudflare may be online, but … Read more
Error 1000 DNS Points to Prohibited IP means Cloudflare refused to serve the request because your DNS record points to an IP or routing setup Cloudflare does not allow. Cloudflare’s official documentation says this error indicates that a Cloudflare DNS record points to a prohibited IP and blocks access to the requested domain. :contentReference[oaicite:0]{index=0} This … Read more
Error 1015 You Are Being Rate Limited means Cloudflare temporarily blocked access because too many requests were made in a short period. Cloudflare’s official documentation says this happens when the website owner has configured rate limiting rules that restrict how many requests a visitor can make in a given time period. :contentReference[oaicite:0]{index=0} This is not … Read more
Error 1033 Argo Tunnel Error means Cloudflare cannot find a healthy tunnel connector to receive traffic for the hostname. Cloudflare’s official documentation states that a 1033 error appears when the tunnel is not connected to Cloudflare’s network because Cloudflare cannot find a healthy cloudflared instance to receive the request. :contentReference[oaicite:0]{index=0} This is not a normal … Read more
NET::ERR_CERT_WEAK_SIGNATURE_ALGORITHM means the browser rejected the website certificate because it was signed with a cryptographic algorithm that is no longer considered secure. In practice, this usually points to legacy certificates that still rely on SHA-1 or similarly outdated signing methods that modern browsers distrust. :contentReference[oaicite:0]{index=0} This is not a cosmetic warning. It is a certificate … Read more
HSTS error usually appears when a browser is forced to use HTTPS for a website, but the site’s certificate or secure connection is broken. HSTS stands for HTTP Strict Transport Security, a policy that tells browsers to connect to the site only over HTTPS and not allow fallback to HTTP. :contentReference[oaicite:0]{index=0} This is why HSTS … Read more
SEC_ERROR_UNKNOWN_ISSUER means Firefox does not trust the certificate issuer presented by the website. In plain language, Firefox cannot build a trusted certificate chain from the website certificate back to a known, trusted root certificate, so it blocks the connection as a security risk. :contentReference[oaicite:0]{index=0} This error is common on sites with broken certificate chains, self-signed … Read more
PR_END_OF_FILE_ERROR is a Firefox-specific secure connection error. It usually appears when Firefox cannot complete the HTTPS connection because something on the path interrupts or breaks the TLS handshake before a trusted secure session is established. :contentReference[oaicite:0]{index=0} This error is common on sites that otherwise work in Chrome or Edge, which makes it confusing. In real … Read more