title: DynamoDBMapper unconvert attribute error when converting Dynamo JSON to POJO (SAME POJO which i persisted in DYNAMO)
body: <p>I Have a Java object which i persist in dynamo DB . Java object contains MAP, LIST, STRING , INT, OBJECTS etc. Values are getting saved in dynamodb using <code>@DynamoDBDocument</code> , <code>@DynamoDBAttribute</code> etc , but when i try to fetch a value it shows up an error</p>
  
  <blockquote>
    <p>"2018-06-14 16:15:38.957 ERROR 93104 --- [nio-8081-exec-1]
    o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet
    [dispatcherServlet] in context with path [] threw exception [Request
    processing failed; nested exception is
    com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMappingException:
    InvoiceModel[recurringInvoiceDetail]; could not unconvert attribute]
    with root cause</p>
    
    <p>java.lang.NullPointerException: null"</p>
    
    <p>InvoiceModel is my POJO and recurringInvoiceDetail is a class member
    which is an object.</p>
  </blockquote>
  
  <p>Does anyone knows how i can fix this issue ?</p>
  
  <p>Thanks in advance!</p>