JPA Glassfish Database Update Issue

Question

I have an application deployed on Glassfish v3.0.1 which reads events from a table in my database. Once ready it marks them as processed. I am getting a strange error I can\

Answer 1

I had this same Error but mine was caused from this:

the function:

public List getDistinctSaleSpecies()
    {
        return ejbFacade.getDistinctSpeciesForAllSales();
    }

when i changed the set tag to this it worked: