java.lang.AssertionError: null TypeElement for "prdel.DiscountCode"
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator$EntityClassGenerator.generateRelationship(JavaPersistenceGenerator.java:931)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator$ClassGenerator.run(JavaPersistenceGenerator.java:676)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator$1.run(JavaPersistenceGenerator.java:441)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator$1.run(JavaPersistenceGenerator.java:437)
        at org.netbeans.api.java.source.JavaSource$1.run(JavaSource.java:653)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:129)
        at org.netbeans.modules.parsing.api.ParserManager$UserTaskAction.run(ParserManager.java:113)
        at org.netbeans.modules.parsing.impl.TaskProcessor.runUserTask(TaskProcessor.java:190)
        at org.netbeans.modules.parsing.api.ParserManager.parse(ParserManager.java:99)
        at org.netbeans.api.java.source.JavaSource.runModificationTask(JavaSource.java:669)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator.runImpl(JavaPersistenceGenerator.java:437)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator$Generator.run(JavaPersistenceGenerator.java:349)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator.generateBeans(JavaPersistenceGenerator.java:203)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.JavaPersistenceGenerator.generateBeans(JavaPersistenceGenerator.java:175)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.RelatedCMPWizard.createBeans(RelatedCMPWizard.java:366)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.RelatedCMPWizard.access$000(RelatedCMPWizard.java:87)
        at org.netbeans.modules.j2ee.persistence.wizard.fromdb.RelatedCMPWizard$1.run(RelatedCMPWizard.java:278)
        at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:602)
        at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:1084)
Caused: org.openide.util.RequestProcessor$FastItem: task failed due to: java.lang.AssertionError: null TypeElement for "prdel.DiscountCode"