Schema, contract, and parameter constraint validation failures.
Last reviewed: March 2, 2026|64 mapped errors|Page 4 of 5
Validation errors indicate request payload, query parameters, or API contract expectations were not satisfied by caller input.
Provider-specific error pages mapped to this category (64 total). Showing 46-60.
Azure returns `StorageAccountAlreadyTaken` when the requested storage account name is already in use globally.
ARM returns `SubscriptionNotFound` when the deployment subscription cannot be accessed due to wrong subscription ID, format, or insufficient access.
Azure returns `ValidationError` when request values violate provider-side semantic rules, even if request syntax is structurally valid.
GCP INVALID_ARGUMENT means request input is malformed or violates API constraints, independent of current resource state.
GCP INVALID_REQUEST is typically a service-specific reason indicating malformed or semantically unsupported request composition.
GCP OK means the operation completed successfully. In HTTP-mapped APIs this corresponds to HTTP 200 and is a success status, not an error condition.
HTTP 200 OK means the request succeeded and the server is returning a representation of the target resource in the response body.
HTTP 207 Multi-Status is a success response indicating that the server has processed a batch request and the body contains multiple independent status codes for each sub-operation. It allows for "Partial Success," where some items in a batch succeed while others fail.
HTTP 400 Bad Request means the server cannot process the request because syntax, framing, or parameters are invalid.
HTTP 405 Method Not Allowed means the resource exists but does not support the HTTP method used.
HTTP 406 Not Acceptable means the server cannot produce a representation matching proactive negotiation headers.
HTTP 411 Length Required means the server requires a defined Content-Length for this request.
HTTP 413 Content Too Large means the request body exceeds the size limit accepted by the server.
HTTP 414 URI Too Long means the target URI is longer than the server is willing or able to interpret.
HTTP 415 Unsupported Media Type means request payload format is not supported for this method or resource.
Compare Guide
Fix API payload issues faster by using 400 for malformed syntax and 422 for semantic validation failures, so clients correct format before business rules.
Playbook
Use this playbook to separate browser-enforced cross-origin policy failures from server-side CORS header and route defects and apply strict origin and credential controls safely.
Playbook
Use this playbook to separate malformed-request failures from semantic validation failures, then fix request contracts without broad server-side bypasses.
Contract expectations can change by version. If client and server versions drift, previously accepted fields or formats can become invalid.
Capture and diff full request payloads against a known-good example, then validate each field against the live API schema and constraints.
No. 400 is a broad class. Confirm whether the failure is contract validation, authentication syntax, or malformed transport metadata.