I meant the example was done in jbpm 5.0 and currently you are trying to deploy the same on jbpm 5.2
Looks like there were some change in the entities and found a change in the named queries in the orm .xml .
I changed my orm.xml and that basically made the example work for me .
I have attached the orm.xml that is working for me in the previous reply. Try using that.
Hope it helps
Cheers :)