Error map
415 HTTP 415 Unsupported Media Type
HTTP · layer 2, Network
Centre: this error. First ring: errors it is linked with (7). Outer ring: what those are linked with. Colours show the layer of a request each error belongs to. Click any dot to re-centre the map on it; hover to follow its connections. The centre dot opens the error page.
Directly related (7)
HTTP 400 Bad Request
The server could not understand the request because its syntax, headers or body are malformed or invalid.
HTTP 422 Unprocessable Content
The request is well-formed, but the data fails validation (e.g. invalid email, missing required field).
API Error: Malformed JSON in request body (entity.parse.failed / JSON parse error)
The server couldn’t parse the request body as JSON, so it rejected the request before looking at any field.
Upload error: File type not allowed / unsupported file type
The upload was rejected because the file’s type — extension, MIME type or actual content — isn’t on the allowed list.
Unsupported Media Type
The API cannot process the request because the media type or Content-Type format is not supported by the endpoint.
HTTP 406 Not Acceptable
The server can’t produce a response in any format listed in the request’s Accept headers.
API Error: Missing required parameter (parameter_missing / "x" is required)
The API rejected the request because a field it requires — in the query string, path, headers or JSON body — wasn’t sent or was e…
Two steps away (18)
HTTP 401 Unauthorized
The request has no valid authentication credentials — you need to log in or send a valid token.
HTTP 405 Method Not Allowed
The URL exists, but it doesn’t accept the HTTP method you used (e.g. POST to a GET-only route).
HTTP 413 Content Too Large (Request Entity Too Large)
The request body is bigger than the server is willing to accept — usually a file upload over the configured limit.
HTTP 409 Conflict
The request conflicts with the current state of the resource — e.g. a duplicate or an edit based on an outdated version.
MySQL ERROR 1406: Data too long for column
The value is longer than the column allows (e.g. 300 characters into VARCHAR(255)), and strict mode rejects it instead of truncat…
java.lang.NumberFormatException: For input string: "x"
A string couldn’t be parsed as a number — it’s empty, has spaces/commas, is too large, or isn’t numeric.
SyntaxError: Unexpected token < in JSON at position 0
`JSON.parse()` / `response.json()` received something that isn’t JSON — very often an HTML error page.
HTTP 411 Length Required
The server refuses a request with a body but no Content-Length header.
com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize value of type `java.util.ArrayList` from Object value
Jackson found JSON whose shape doesn’t match the target Java type (object vs array, string vs number, missing constructor).
WordPress: The link you followed has expired
Usually an upload (theme, plugin, media) larger than PHP’s upload/post limits — WordPress receives an empty request and shows thi…
WordPress: Sorry, you are not allowed to access this page.
Your user role lacks the capability for that admin screen — or the database table prefix / user capabilities are out of sync afte…
API Error: Invalid type — expected integer, received string
A request field has the wrong data type — a string where the API expects a number, a number where it expects a boolean, an object…
HTTP 403 Forbidden
The server understood the request but refuses to authorize it — you (or the server process) are not allowed to access this resour…
HTTP 506 Variant Also Negotiates
The server encountered an internal configuration error because the requested resource is configured to use transparent content ne…
Chrome: This page isn’t working — sent an invalid response. ERR_CONTENT_DECODING_FAILED
The response claims to be compressed (gzip/brotli) but cannot be decompressed — it was double-compressed, truncated or not compre…
API Error: Invalid parameter value — must be one of the allowed values / out of range
The field has the right type but a value the API doesn’t allow — not in the list of accepted options, too small or large, too lon…
API Error: Request failed schema validation (must NOT have additional properties / Additional properties are not allowed)
The JSON body doesn’t match the endpoint’s schema — an unknown property, wrong nesting, or a missing required object.
API Error: Invalid date format — expected ISO 8601 (YYYY-MM-DDTHH:mm:ssZ)
A date or timestamp in the request isn’t in the format the API expects — usually ISO 8601 with a time zone, or a Unix timestamp.
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