I use primefaces's p:selectManyMenu. When I submit the value, it always report validation error Illegal selection options. Can you help to solve this issue? 
JSF code:
 <h:outputLabel for="scenario" value="GivenStories:" /> 
    <p:selectManyMenu id="givenstoryselect" value="#{anotherDynaFormController.selectedGivenStory}" converter="scenarioConverter" var="g" style="width:500px;height:70px;align:left;" showCheckbox="true" > 
    <f:selectItems value="#{anotherDynaFormController.givenStorys}" var="scenario" itemLabel="#{scenario.name}" itemValue="#{scenario}"  /> 
    <p:column>#{g.name}</p:column>
    </p:selectManyMenu>
Bean class:
//converter    
@FacesConverter(value="scenarioConverter")
public class ScenarioConverter implements Converter {       
    public static List<Scenario> scenarioDB = new ArrayList<Scenario>();
    private ScenarioDao scenarioDao = new ScenarioDao();
    public Object getAsObject(FacesContext facesContext, UIComponent component, String submittedValue) {
        if (submittedValue.trim().equals("")) {
            return null;
        } else {
            try {
                int number = Integer.parseInt(submittedValue);
                scenarioDB = scenarioDao.findAll();
                for (Scenario p : scenarioDB) {
                    if (p.getId() == number) {
                        return p;
                    }
                }
            } catch(NumberFormatException exception) {
                throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Conversion Error", "Not a valid scenario"));
            }
        }        
        return null;
    }  
    public String getAsString(FacesContext facesContext, UIComponent component, Object value) {
        if (value == null) {
            return null;
        } else {
            return String.valueOf(((Scenario) value).getId());
        }
    }
}
@ManagedBean  
@ViewScoped  
public class AnotherDynaFormController extends SuperBean implements Serializable  {        
    private List<Scenario> givenStorys;
    private List<Meta> selectedMetas;
    private List<Scenario> selectedGivenStory;
    private List<ProjectTree> parents;
public DynaFormModel getModel() { 
  givenStorys = scenarioDao.findAll();
  ...
}
...
}
 
    