JSF SelectOneMenu not working without converter? - jsf

Question

So I have the following xhtml code:
<p:cellEditor>
<f:facet name="output">
<h:outputText value="#{interview.interviewer.name}" />
</f:facet>
<f:facet name="input">
<p:selectOneMenu value="#{interview.interviewer}" style="width:100%" converter="interviewerConverter">
<f:selectItems value="#{interviewerController.allInterviewers}" var="s" itemLabel="#{s.name}" itemValue="#{s}" />
</p:selectOneMenu>
</f:facet>
</p:cellEditor>
When I try to edit the data in the cell, I get the following error:
Conversion Error setting value 'com.jpa.entities.Interviewer#288002c2' for 'null Converter'.
I took a look at the similar posts but did not find out what is wrong here.
Also I have created the following converter, with this I do not get a converter error:
#FacesConverter("interviewerConverter")
public class InterviewerConverter implements Converter {
public Object getAsObject(FacesContext fc, UIComponent uic, String value) {
if(value != null && value.trim().length() > 0) {
try {
InterviewerController service = (InterviewerController) fc.getExternalContext().getApplicationMap().get("interviewerController");
return service.getallInterviewers().get(Integer.parseInt(value));
} catch(NumberFormatException e) {
throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Conversion Error", "Not a valid"));
}
}
else {
return null;
}
}
public String getAsString(FacesContext fc, UIComponent uic, Object object) {
if(object != null) {
return String.valueOf(((Interviewer) object).getId());
}
else {
return null;
}
}
}
After implementing the converter, I get a NullPointerException on the following list: (service.getallInterviewers())
return service.getallInterviewers().get(Integer.parseInt(value));
but in the controller, the list is initialized like this:
#PostConstruct
public void init(){
initAllInterviewers();
}
What can be wrong here?