Liferay portlet session error iterator

gistfile1.txt

<%@page import="java.util.Iterator"%>
<%@page import="com.liferay.portal.kernel.servlet.SessionErrors"%>
<%
 Iterator<String> itErrors = SessionErrors.iterator(renderRequest);
 while (itErrors.hasNext()){
     String errorKey =  itErrors.next();      
        %>
	<%=errorKey%>
        <%  
 }
 %>

When your Liferay-ui:error giving trouble to complete your task. Just use the above snippet to itereate and check whether the session error key present.