title: AWS API Gateway: Execution failed due to configuration error: Invalid JSON in response
body: <p>I have an API gateway setup with a Custom Authorizer that calls a Lambda function. For testing purposes I copied the example from here: <a href="http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html#api-gateway-proxy-integration-lambda-function-nodejs" rel="noreferrer">http://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-create-api-as-simple-proxy-for-lambda.html#api-gateway-proxy-integration-lambda-function-nodejs</a></p>
  
  <p>I get the same answer as in the documentation but when I test the authorizer I get this stacktrace:</p>
  
  <pre><code>    Endpoint request body after transformations: {"type":"TOKEN","authorizationToken":"test","methodArn":"arn:aws:execute-api:ap-southeast-2:893445519708:uyue0zqh15/null/GET/"}
      Authorizer result body before parsing: {"statusCode":200,"headers":{"x-custom-header":"my custom header value"},"body":"{\"message\":\"Hello World!\",\"input\":{\"type\":\"TOKEN\",\"authorizationToken\":\"test\",\"methodArn\":\"arn:aws:execute-api:ap-southeast-2:893445519708:uyue0zqh15/null/GET/\"}}"}
      Execution failed due to configuration error: Invalid JSON in response: {"statusCode":200,"headers":{"x-custom-header":"my custom header value"},"body":"{\"message\":\"Hello World!\",\"input\":{\"type\":\"TOKEN\",\"authorizationToken\":\"test\",\"methodArn\":\"arn:aws:execute-api:ap-southeast-2:893445519708:uyue0zqh15/null/GET/\"}}"}
      AuthorizerConfigurationException
  </code></pre>
  
  <p>Why doesn't the authorizer like the JSON response?</p>