Troubleshooting
Debug HTTP Errors
Step-by-step guides for diagnosing and fixing common HTTP failures. Each guide walks through the diagnosis process, common causes, and concrete solutions.
Cookie Not Being Sent
Trace missing cookies through storage, Domain, Path, Secure, SameSite, CORS credentials, expiration, and browser policy.
Failed CORS Preflight
Inspect the OPTIONS exchange and fix mismatched origins, methods, headers, credentials, redirects, or proxy handling.
Debugging CORS Errors
Diagnose and fix cross-origin resource sharing errors. Covers preflight failures, missing headers, and credential misconfigurations.
Debugging 403 Forbidden
Understand why access is denied and how to fix it. Covers auth vs authz, role checks, IP blocks, and CSRF.
Debugging 500 Internal Server Error
Find and fix server-side failures. Covers reading logs, common causes, error handling patterns, and prevention.