Nginx Server-Errors Error Codes

Bad Gateway (Nginx) — the reverse proxy received an invalid response

No Response — Nginx closed the connection without returning an HTTP response

Request Header Too Large — Nginx rejected the request because header data was too large

Client Closed Request — Nginx logged that the client closed the connection first

SSL Certificate Error — an invalid client SSL certificate was presented

SSL Certificate Required — the client failed to present an identity certificate

HTTP Request Sent to HTTPS Port — plain text sent over an encrypted channel