Los códigos de clase 4XX indican que has hecho algo mal. Concretamente, hay un error en el lado del cliente.

HTTP error 400 Bad Request

HTTP error 401 Unauthorized

HTTP error 402 Payment Required

HTTP error 403 Forbidden

HTTP error 404 Not Found

HTTP error 405 Method Not Allowed

HTTP error 406 Not Acceptable

HTTP error 407 Proxy Authentication Required

HTTP error 408 Request Timeout

HTTP error 409 Conflict

HTTP error 410 Gone

HTTP error 411 Length Required

HTTP error 412 Precondition Failed

HTTP error 413 Payload Too Large

HTTP error 414 Request-URI Too Long

HTTP error 415 Unsupported Media Type

HTTP error 416 Requested Range Not Satisfiable

HTTP error 417 Expectation Failed

HTTP error 418 I’m a teapot

HTTP error 419 Authentication Timeout

HTTP error 420

HTTP error 421 Misdirected Request

HTTP error 422 Unprocessable Entity

HTTP error 423 Locked

HTTP error 424 Failed Dependency

HTTP error 425 Too Early

HTTP error 426 Upgrade Required

HTTP error 428 Precondition Required

HTTP error 429 Too Many Requests

HTTP error 431 Request Header Fields Too Large

HTTP error 444 Connection Closed Without Response

HTTP error 449 Retry With

HTTP error 451 Unavailable For Legal Reasons

HTTP error 460

HTTP error 463

HTTP error 464

HTTP error 494 Request Header Too Large

HTTP error 495 SSL Certificate Error

HTTP error 496 SSL Certificate Required

HTTP error 497 HTTP Request Sent to HTTPS Port
