Product Version = NetBeans IDE 7.2.1 (Build 201210100934)
Operating System = Mac OS X version 10.6.8 running on x86_64
Java; VM; Vendor = 1.6.0_37
Runtime = Java HotSpot(TM) 64-Bit Server VM 20.12-b01-434
java.lang.ClassNotFoundException: Will not load class javax.persistence.Persistence arbitrarily from one of ModuleCL@cc749e4[javax.persistence] and ModuleCL@1b0fb9bd[org.netbeans.modules.hibernatelib] starting from ModuleCL@1db5d2b2[it.rdg_software.scuola.api.implement]; see http://wiki.netbeans.org/DevFaqModuleCCE
Created attachment 131394 [details]
Same problem with the CRUD Customer Application if built on scratch fro the Netbeans Tutorial.
It seems impossible to view the persistence.xml.
The problem has born in the moment I did Clean and Build over the Netbeans Platform Application.
Before I was making changes on single modules and the Persistence Library did not any problem.
Everything seemed to function very well until tah moment of Clean and Build over the Netbeans Platform Application.
This was the reason I tried to built from the tutorial but after buiding the viewer component I got the same problem.
Also changed the database driver PostgreSQL with the version useful in the Services tab to make the connection.
but with no result. The topcomponent can't be instantiated because the EntityManager do not find
the persistence library unit, it seems. I repeated the tutorial http://platform.netbeans.org/tutorials/nbm-crud.html#creating-entity