400 - whatever error ..
The error is one of the following:
400 Bad Request - The server cannot or will not process the request due to an apparent client error (e.g., malformed request syntax, size too large, invalid request message framing, or deceptive request routing).
402 Payment Required - Reserved for future use.
405 Method Not Allowed - A request method is not supported for the requested resource; for example, a GET request on a form that requires data to be presented via POST, or a PUT request on a read-only resource.
406 Not Acceptable - The requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request.[39] See Content negotiation.
407 Proxy Authentication Required (RFC 7235) - The client must first authenticate itself with the proxy.
408 Request Timeout - The server timed out waiting for the request. According to HTTP specifications: “The client did not produce a request within the time that the server was prepared to wait. The client MAY repeat the request without modifications at any later time.”
409 Conflict - Indicates that the request could not be processed because of conflict in the current state of the resource, such as an edit conflict between multiple simultaneous updates.
410 Gone - Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed and the resource should be purged. Upon receiving a 410 status code, the client should not request the resource in the future. Clients such as search engines should remove the resource from their indices.[42] Most use cases do not require clients and search engines to purge the resource, and a “404 Not Found” may be used instead.
411 Length Required - The request did not specify the length of its content, which is required by the requested resource.
412 Precondition Failed (RFC 7232) - The server does not meet one of the preconditions that the requester put on the request header fields.
413 Payload Too Large (RFC 7231) - The request is larger than the server is willing or able to process. Previously called “Request Entity Too Large”.
414 URI Too Long (RFC 7231) - The URI provided was too long for the server to process. Often the result of too much data being encoded as a query-string of a GET request, in which case it should be converted to a POST request. Called “Request-URI Too Long” previously.
415 Unsupported Media Type (RFC 7231) - The request entity has a media type which the server or resource does not support. For example, the client uploads an image as image/svg+xml, but the server requires that images use a different format.
416 Range Not Satisfiable (RFC 7233) - The client has asked for a portion of the file (byte serving), but the server cannot supply that portion. For example, if the client asked for a part of the file that lies beyond the end of the file. Called “Requested Range Not Satisfiable” previously.
417 Expectation Failed - The server cannot meet the requirements of the Expect request-header field.
421 Misdirected Request (RFC 7540) - The request was directed at a server that is not able to produce a response[56] (for example because of connection reuse).
422 Unprocessable Entity (WebDAV; RFC 4918) - The request was well-formed but was unable to be followed due to semantic errors.
423 Locked (WebDAV; RFC 4918) - The resource that is being accessed is locked.
424 Failed Dependency (WebDAV; RFC 4918) - The request failed because it depended on another request and that request failed (e.g., a PROPPATCH).
425 Too Early (RFC 8470) - Indicates that the server is unwilling to risk processing a request that might be replayed.
426 Upgrade Required - The client should switch to a different protocol such as TLS/1.3, given in the Upgrade header field.
428 Precondition Required (RFC 6585) - The origin server requires the request to be conditional. Intended to prevent the ‘lost update’ problem, where a client GETs a resource’s state, modifies it, and PUTs it back to the server, when meanwhile a third party has modified the state on the server, leading to a conflict.
429 Too Many Requests (RFC 6585) - The user has sent too many requests in a given amount of time. Intended for use with rate-limiting schemes.
431 Request Header Fields Too Large (RFC 6585) - The server is unwilling to process the request because either an individual header field, or all the header fields collectively, are too large.[59]
451 Unavailable For Legal Reasons (RFC 7725) - A server operator has received a legal demand to deny access to a resource or to a set of resources that includes the requested resource.[60] The code 451 was chosen as a reference to the novel Fahrenheit 451 (see the Acknowledgements in the RFC).
501 Not Implemented - The server either does not recognize the request method, or it lacks the ability to fulfil the request. Usually this implies future availability (e.g., a new feature of a web-service API).
504 Gateway Timeout - The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.[67]
505 HTTP Version Not Supported - The server does not support the HTTP protocol version used in the request.[68]
506 Variant Also Negotiates (RFC 2295) - Transparent content negotiation for the request results in a circular reference.[69]
507 Insufficient Storage (WebDAV; RFC 4918) - The server is unable to store the representation needed to complete the request.[16]
508 Loop Detected (WebDAV; RFC 5842) - The server detected an infinite loop while processing the request (sent instead of 208 Already Reported).
510 Not Extended (RFC 2774) - Further extensions to the request are required for the server to fulfil it.[70]
511 Network Authentication Required (RFC 6585) - The client needs to authenticate to gain network access. Intended for use by intercepting proxies used to control access to the network (e.g., “captive portals” used to require agreement to Terms of Service before granting full Internet access via a Wi-Fi hotspot). Unofficial codes
103 Checkpoint - Used in the resumable requests proposal to resume aborted PUT or POST requests.[71]
218 This is fine (Apache Web Server) - Used as a catch-all error condition for allowing response bodies to flow through Apache when ProxyErrorOverride is enabled.[dubious – discuss] When ProxyErrorOverride is enabled in Apache, response bodies that contain a status code of 4xx or 5xx are automatically discarded by Apache in favor of a generic response or a custom response specified by the ErrorDocument directive.
419 Page Expired (Laravel Framework) - Used by the Laravel Framework when a CSRF Token is missing or expired.
420 Method Failure (Spring Framework) - A deprecated response used by the Spring Framework when a method has failed.
420 Enhance Your Calm (Twitter) - Returned by version 1 of the Twitter Search and Trends API when the client is being rate limited; versions 1.1 and later use the 429 Too Many Requests response code instead. The phrase “Enhance your calm” comes from the 1993 movie Demolition Man, and its association with this number is likely a reference to cannabis.
430 Request Header Fields Too Large (Shopify) - Used by Shopify, instead of the 429 Too Many Requests response code, when too many URLs are requested within a certain time frame.
450 Blocked by Windows Parental Controls (Microsoft) - The Microsoft extension code indicated when Windows Parental Controls are turned on and are blocking access to the requested webpage.
498 Invalid Token (Esri) - Returned by ArcGIS for Server. Code 498 indicates an expired or otherwise invalid token.
499 Token Required (Esri) - Returned by ArcGIS for Server. Code 499 indicates that a token is required but was not submitted.
509 Bandwidth Limit Exceeded (Apache Web Server/cPanel) - The server has exceeded the bandwidth specified by the server administrator; this is often used by shared hosting providers to limit the bandwidth of customers.
529 Site is overloaded - Used by Qualys in the SSLLabs server testing API to signal that the site can’t process the request.
530 Site is frozen - Used by the Pantheon web platform to indicate a site that has been frozen due to inactivity.
598 (Informal convention) Network read timeout error - Used by some HTTP proxies to signal a network read timeout behind the proxy to a client in front of the proxy.
440 Login Time-out - The client’s session has expired and must log in again.
449 Retry With - The server cannot honour the request because the user has not provided the required information.
451 Redirect - Used in Exchange ActiveSync when either a more efficient server is available or the server cannot access the users' mailbox.[84] The client is expected to re-run the HTTP AutoDiscover operation to find a more appropriate server.
444 No Response - Used internally to instruct the server to return no information to the client and close the connection immediately.
494 Request header too large - Client sent too large request or too long header line.
495 SSL Certificate Error - An expansion of the 400 Bad Request response code, used when the client has provided an invalid client certificate.
496 SSL Certificate Required - An expansion of the 400 Bad Request response code, used when a client certificate is required but not provided.
497 HTTP Request Sent to HTTPS Port - An expansion of the 400 Bad Request response code, used when the client has made a HTTP request to a port listening for HTTPS requests.
499 Client Closed Request - Used when the client has closed the request before the server could send a response.
Well .. whatever (rolls eyes) .. I’m quite sure it’s you making the fuckup, not me. So don’t you dare trying to lay this upon me buster! (I got your number).