I am facing the problem, whenever I am trying to write selectItems tag in SelectOneMenu parent tag, it occurs. I am unable to find out why this illegalArgumentException is coming. Although value is coming in the list. But when Iam submitting the form it is giving exception. I am creating List of SelectItem object but dont know, why? When I am using hard coded selecItem tag it is not giving any errors only while using selectItems...I searched a lot lot but never able to find out a satisfactory reason nor solution...I will provide my code..jst have a look at it..