HTTP 404 means the requested resource was not found at the routing layer that answered the request. Verify the exact URL, host, rewrite rules, deployment path and upstream routing before creating redirects or restoring files.
Step-by-step checks
Capture the exact host, path, query and method and confirm DNS sends the request to the intended site/environment.
Compare the route against the application/router configuration and check whether a reverse proxy strips or adds a path prefix.
Inspect web-server/application access logs to determine which layer generated the 404 and whether the request reached the expected virtual host/application.
For recently moved content, verify deployment artifacts and canonical redirects, avoiding blanket redirects that turn genuine missing resources into misleading success responses.
Useful verification commands
Use commands only on systems you administer and capture the read-only output before making a configuration change.
curl -I https://example.com/missing-path
Resolve-DnsName example.com
How to validate the result
The intended canonical URL must return the expected resource, while genuinely unknown URLs continue to return a proper 404 rather than an unrelated redirect.