X cannot be added because it is already mapped to the entities. X entity class and the entity is not in current project source

Question

I'm creating a new NetBeans EE Enterprise Application, and when I try to create Entity classes from database (Customer from the sample database), I can't select it because of this error :

Any idea? I'm using NetBeans 7.3 with Glassfish 3.1.2.

Answer 1

I found the answer after spending the last few hours searching in Google. Delete the cache folder in the following

C:\Users\yourusername\AppData\Local\NetBeans\Cache

It solved the problem for me.