Schema, contract, and parameter constraint validation failures.
Last reviewed: February 13, 2026|54 mapped errors|Page 1 of 4
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 (54 total). Showing 1-15.
AWS AmbiguousGrantByEmailAddress means the ACL grantee email address is associated with more than one AWS account, so Amazon S3 cannot resolve a single principal (HTTP 400).
AWS BadDigest means the Content-MD5 or checksum value in the request does not match what Amazon S3 received for that payload (HTTP 400).
AWS CredentialsNotSupported (Credentials Not Supported) means the request type does not support credentials. In Amazon S3, this error returns HTTP 400.
AWS CrossLocationLoggingProhibited (Cross Location Logging Prohibited) means server access logging cannot target a bucket in another AWS Region. In Amazon S3, this error returns HTTP 403.
AWS EntityTooSmall (Entity Too Small) means a multipart upload part is below the minimum allowed size (except the final part). In Amazon S3, this error returns HTTP 400.
AWS ExpiredToken (Expired Token) means the provided token has expired. In Amazon S3, this error returns HTTP 400.
AWS IllegalVersioningConfigurationException (Illegal Versioning Configuration Exception) means the versioning configuration in the request is not valid. In Amazon S3, this error returns HTTP 400.
AWS IncompleteBody (Incomplete Body) means the number of bytes sent is lower than the Content-Length header value. In Amazon S3, this error returns HTTP 400.
AWS IncorrectNumberOfFilesInPostRequest (Incorrect Number Of Files In Post Request) means S3 POST upload requires exactly one file payload. In Amazon S3, this error returns HTTP 400.
AWS InlineDataTooLarge (Inline Data Too Large) means inline data exceeds the maximum allowed size. In Amazon S3, this error returns HTTP 400.
AWS InvalidAction (Invalid Action) means the action or operation requested is invalid. In AWS APIs, this error returns HTTP 400.
CloudFront returns `InvalidArgument` when one or more request parameters are invalid, so the distribution operation is rejected with HTTP 400.
AWS InvalidArgument (Invalid Argument) means one or more request arguments are invalid, missing, or in the wrong format. In Amazon S3, this error returns HTTP 400.
AWS InvalidBucketName (Invalid Bucket Name) means the specified bucket name is invalid for Amazon S3 naming rules. In Amazon S3, this error returns HTTP 400.
AWS InvalidClientTokenId (Invalid Client Token Id) means the AWS access key ID or client token does not exist in records. In AWS APIs, this error returns HTTP 403.
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.