Hi,
Isn't your code similar to this one https://github.com/droolsjbpm/jbpm/blob/master/jbpm-examples/src/main/java/org/jbpm/examples/humantask/HumanTaskExample.java
?
look at this section at that code:
Task task = taskClient.getTask(task4.getId());
Content content = taskClient.getContent(task.getTaskData().getDocumentContentId());
Object result = ContentMarshallerHelper.unmarshall(content.getContent(), null);
Maybe you can use
ContentMarshallerHelper.unmarshall(..) ?
Since you are using jBPM5.3, the
ContentMarshallerHelper.unmarshall(..) will take 3 parameters if I remember correctly, just try with null for second and third parameter.
Regards,
Thomas Setiabudi