title: AWS IoT - Dynamo Insert record failed
body: <p>I am trying to update DynamoDB and I send JSON data from Rasperry PI or MQTT Client, but when I look to CloudWatch I see below error message.</p>
  
  <p><em>EVENT:DynamoActionFailure TOPICNAME:iotbutton/test CLIENTID:MQTT_FX_Client MESSAGE:Dynamo Insert record failed. The error received was Attribute name must not be null or empty. Message arrived on: iotbutton/test, Action: dynamo, Table: myTable_IoT, HashKeyField: SerialNumber, HashKeyValue: ABCDEFG12345, RangeKeyField: Some(ClickType), RangeKeyValue: SINGLE</em></p>
  
  <p>I am using the AWS IoT Tutorial (<a href="http://docs.aws.amazon.com/iot/latest/developerguide/iot-dg.pdf" rel="nofollow noreferrer">http://docs.aws.amazon.com/iot/latest/developerguide/iot-dg.pdf</a>),  The Seccion: Creating a DynamoDB Rule. </p>
  
  <p>The data I send to the IoT platform is:</p>
  
  <pre><code>{
   "serialNumber" : "ABCDEFG12345",
   "clickType" : "SINGLE",
   "batteryVoltage" : "5v USB"
  }
  </code></pre>
  
  <p>topic: <em>iotbutton/ABCDEFG12345</em></p>
  
  <p>Does anyone come across this error and aware of any solution?</p>
  
  <p>Thanks, regards.</p>