411 Length Required

411 Length Required indicates that the server will not accept the request without a valid Content-Length header. Some servers require this header to allocate resources before processing the request body, particularly for large file uploads or streaming data.

• HTTP client not sending Content-Length with POST/PUT requests
• Chunked transfer encoding where server doesn't support it
• Misconfigured HTTP library or custom HTTP client

• Add the Content-Length header with the correct byte count of the request body
• If using chunked encoding, verify the server supports Transfer-Encoding: chunked
• Update your HTTP client library to automatically set Content-Length