Olá, tentei aplicar os ensinamentos para conseguir o retorno da minha tabela pelo ID porém tenho a mensagem anexa. alguém sabe oq pode ser? | Amazon API Gateway: integrando e protegendo serviços

{
  "Output": {
    "__type": "com.amazon.coral.service#SerializationException",
    "Message": null
  },
  "Version": "1.0"
}

Execution log for request 523012f8-a00a-11e9-bf0e-673978eaee85
Sat Jul 06 16:23:00 UTC 2019 : Starting execution for request: 523012f8-a00a-11e9-bf0e-673978eaee85
Sat Jul 06 16:23:00 UTC 2019 : HTTP Method: GET, Resource Path: /listar/2
Sat Jul 06 16:23:00 UTC 2019 : Method request path: {id=2}
Sat Jul 06 16:23:00 UTC 2019 : Method request query string: {}
Sat Jul 06 16:23:00 UTC 2019 : Method request headers: {}
Sat Jul 06 16:23:00 UTC 2019 : Method request body before transformations: 
Sat Jul 06 16:23:00 UTC 2019 : Endpoint request URI: https://events.us-east-1.amazonaws.com/?Action=Scan
Sat Jul 06 16:23:00 UTC 2019 : Endpoint request headers: {Authorization=*************************************************************************************************************************************************************************************************************************************************************************7bc758, X-Amz-Date=20190706T162300Z, x-amzn-apigateway-api-id=lssy4bswv8, Accept=application/json, User-Agent=AmazonAPIGateway_lssy4bswv8, X-Amz-Security-Token=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 [TRUNCATED]
Sat Jul 06 16:23:00 UTC 2019 : Endpoint request body after transformations: {
    "TableName": "ContagemCollection",
    "FilterExpression": "id = :v1",
    "ExpressionAttributeValues": {
    ":v1": {"N": "2'}
    }
}
Sat Jul 06 16:23:00 UTC 2019 : Sending request to https://events.us-east-1.amazonaws.com/?Action=Scan
Sat Jul 06 16:23:00 UTC 2019 : Received response. Status: 200, Integration latency: 107 ms
Sat Jul 06 16:23:00 UTC 2019 : Endpoint response headers: {x-amzn-RequestId=07c51ab2-840b-4b5a-84a6-78cbdf8af49f, Content-Type=application/json, Content-Length=102, Date=Sat, 06 Jul 2019 16:22:59 GMT}
Sat Jul 06 16:23:00 UTC 2019 : Endpoint response body before transformations: {"Output":{"__type":"com.amazon.coral.service#SerializationException","Message":null},"Version":"1.0"}
Sat Jul 06 16:23:00 UTC 2019 : Method response body after transformations: {"Output":{"__type":"com.amazon.coral.service#SerializationException","Message":null},"Version":"1.0"}
Sat Jul 06 16:23:00 UTC 2019 : Method response headers: {X-Amzn-Trace-Id=Root=1-5d20cae4-7451f01bf918f317b2117a23, Content-Type=application/json}
Sat Jul 06 16:23:00 UTC 2019 : Successfully completed execution
Sat Jul 06 16:23:00 UTC 2019 : Method completed with status: 200