ResourceNotFoundException
AWS ResourceNotFoundException (Resource Not Found Exception) means the target resource for that service operation cannot be found in the active request scope. Many AWS APIs return HTTP 404 for this error, while some services use HTTP 400.
Last reviewed: February 12, 2026|Editorial standard: source-backed technical guidance
What Does Resource Not Found Exception Mean?
The operation reached the service successfully, but the referenced resource is unresolved in that account/region/state context, so downstream workflow steps stop on lookup failure.
Common Causes
- -Resource identifier (ARN/ID/name) does not match an existing resource for the target service.
- -Request is sent to the wrong account, region, or partition for that resource.
- -Resource was deleted, renamed, or is still transitioning to an ACTIVE/ready state.
- -Client cached stale identifiers after infrastructure changes.
How to Fix Resource Not Found Exception
- 1Validate the exact ARN/ID against service inventory in the same account and region.
- 2Confirm caller context with `sts:GetCallerIdentity` and operation endpoint region.
- 3Use service-specific `Get/List/Describe` APIs to verify existence and state before retry.
- 4Retry only when recent create/update operations may still be propagating or converging to active state.
Step-by-Step Diagnosis for Resource Not Found Exception
- 1Capture request ID, full resource identifier, and endpoint region from the failing call.
- 2Correlate CloudTrail lifecycle events (create/update/delete) around the failure window.
- 3Compare IaC outputs and runtime config values for stale or drifted identifiers.
- 4Check service-specific readiness state requirements before first dependent call.
Identifier Scope Validation
- -Verify ARN/ID/name against the same account, region, and partition as the failing endpoint (example: identifier exists in `us-east-1` but request targets `eu-west-1`).
- -Inspect runtime config sources for stale IDs after deploy (example: old Terraform output cached in parameter store).
Lifecycle and Propagation Checks
- -Audit create/delete timelines and control-plane convergence windows (example: dependent read runs before resource reaches ACTIVE state).
- -Confirm dependency ordering between provisioning and first use (example: app startup calls resource before bootstrap stack has completed).
How to Verify the Fix
- -Re-run the same service operation and confirm ResourceNotFoundException no longer appears.
- -Validate dependent workflows complete with the corrected resource reference.
- -Confirm resource lookup error rates return to baseline.
How to Prevent Recurrence
- -Use dynamic discovery or deployment outputs instead of hard-coded resource IDs in application configs.
- -Add readiness/state checks between resource creation and dependent operations.
- -Continuously detect identifier drift between IaC state and runtime configuration.
Pro Tip
- -emit immutable resource references from deploy pipelines and block app rollout when runtime-resolved IDs do not match those artifacts.
Decision Support
Compare Guide
HTTP 400 vs 422: Bad Request vs Unprocessable Content
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
Resource State Playbook (404 / 410 / ResourceNotFound)
Use this playbook to separate temporary missing-resource lookups from permanent removals, then fix scope, lifecycle, and identifier drift safely.
Playbook
CORS Error Fix Playbook (Preflight / Origin / Credentials)
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.
Official References
Provider Context
This guidance is specific to AWS services. Always validate implementation details against official provider documentation before deploying to production.