Troubleshooting SSL_ERROR_RX_RECORD_TOO_LONG Configuration Errors

The SSL_ERROR_RX_RECORD_TOO_LONG error represents one of the more cryptic SSL/TLS errors that administrators encounter, typically appearing in Firefox with this specific error code while Chrome might display "ERR_SSL_PROTOCOL_ERROR" and other browsers show various protocol-related error messages. Despite its technical-sounding name, this error usually stems from straightforward configuration mistakes rather than actual protocol violations. The error occurs when browsers expect to receive SSL/TLS encrypted data but instead receive plain HTTP responses, causing the SSL/TLS parser to interpret HTML or HTTP headers as malformed SSL records.

This error particularly frustrates administrators because it often appears after seemingly correct SSL certificate installation. The certificates themselves might be perfectly valid, properly signed, and correctly chained, yet users still cannot establish secure connections. The error tends to manifest inconsistently - sometimes affecting only certain URLs, specific port configurations, or particular virtual hosts while others work correctly. This inconsistency can lead to hours of troubleshooting certificates when the actual problem lies in web server configuration.