(AccessDeniedException) when calling the PutParameter operation: null (Service: AWSKMS …)

If you’re trying to set a parameter value in AWS Systems Manager Parameter Store you might get this error:

An error occurred (AccessDeniedException) when calling the PutParameter operation: null (Service: AWSKMS; Status Code: 400; Error Code: AccessDeniedException; Request ID: xxxxxx; Proxy: null)

You can see the service “AWSKMS” here which indicates that the error is coming from KMS, even though you’re making a call to AWS Systems Manager Parameter Store.