I have example web application Hibernate 4.3.5 + Derby database 10.10.1.1+ Glassfish4.0 with IDE NetBeans 8.0Beta.
I have the next exception:
Caused
There is one more chance to get this exception even we used class name i.e., if we have two classes with same name in different packages. we'll get this problem.
I think hibernate may get ambiguity and throws this exception, so the solution is to use complete qualified name(like com.test.Customerv)
I added this answer that will help in scenario as I mentioned. I got the same scenario got stuck for some time.