Our AWS error library covers high-impact exceptions across S3, IAM, EC2, Lambda, and DynamoDB with service-specific diagnostics. Each entry is written for incident workflows using RequestId and HostId evidence, policy scope checks, and quota or regional constraint analysis.
These are the highest-signal AWS pages for common production failures and the best first routes for internal linking and early user navigation.
Priority guide
Access Denied
Fix AWS AccessDenied with policy-layer diagnostics across IAM, SCP, resource policies, and trust rules to restore least-privilege access safely.
->Priority guide
Authentication Failure
Fix AWS AuthFailure: Learn the difference between authentication and authorization, validate IAM access keys, and resolve credential rotation sync iss...
->Priority guide
Throttling Exception
Fix AWS ThrottlingException with adaptive rate control, exponential backoff with jitter, and quota-aware traffic shaping for stable API behavior.
->When you need broader context, move from provider-specific pages into the matching error category or incident playbook before changing production behavior.
Showing 91-100 of 100.
AWS ThrottlingException means the service rejected request rate or concurrency beyond allowed limits. Depending on service and protocol, this commonly returns HTTP 400 or HTTP 429.
AWS TokenRefreshRequired means the temporary token in the request must be refreshed before Amazon S3 will accept the operation. In Amazon S3, this error returns HTTP 400.
AWS TooManyDistributions means processing the CloudFront request would exceed the account limit for distributions (HTTP 400).
AWS TooManyRequestsException is a Lambda-specific throttling error indicating that the function has reached its concurrency limit at either the function or account level. The request is rejected immediately without execution to protect the regional infrastructure.
AWS TransactionConflictException means a DynamoDB transactional request conflicted with another concurrent item update (HTTP 400).
AWS Unavailable (Unavailable) means the service is temporarily unavailable. In AWS APIs, this error returns HTTP 503.
IAM returns `UnmodifiableEntity` when a protected resource, typically a service-linked role, is managed only by the owning AWS service and cannot be changed directly. IAM returns HTTP 400 for this condition.
AWS UnsupportedOperation means the requested EC2 operation is not supported for the selected instance, AMI, or resource configuration.
AWS ValidationException (Validation Exception) means the input fails service validation constraints. In AWS APIs, this error returns HTTP 400.
Amazon EC2 VolumeInUse means an EBS volume is still attached, detaching, or otherwise not in the required available state for the requested operation.