JPA: Class cast exception during removing generators from package-info.java in JPA details view

org.eclipse.swt.SWTException: Failed to execute runnable (java.lang.ClassCastException: org.eclipse.jpt.jpa.core.internal.resource.java.source.SourcePackage cannot be cast to org.eclipse.jpt.jpa.core.resource.java.JavaResourcePersistentMember)
at org.eclipse.swt.SWT.error(SWT.java:4282)
at org.eclipse.swt.SWT.error(SWT.java:4197)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:138)
at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:3563)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3212)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
at org.eclipse.jface.window.Window.open(Window.java:801)
at org.eclipse.ui.internal.views.log.EventDetailsDialog.open(EventDetailsDialog.java:180)
at org.eclipse.ui.internal.views.log.EventDetailsDialogAction.run(EventDetailsDialogAction.java:98)
at org.eclipse.ui.internal.views.log.LogView$15.doubleClick(LogView.java:535)
at org.eclipse.jface.viewers.StructuredViewer$1.run(StructuredViewer.java:845)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.StructuredViewer.fireDoubleClick(StructuredViewer.java:843)
at org.eclipse.jface.viewers.AbstractTreeViewer.handleDoubleSelect(AbstractTreeViewer.java:1462)
at org.eclipse.jface.viewers.StructuredViewer$4.widgetDefaultSelected(StructuredViewer.java:1246)
at org.eclipse.jface.util.OpenStrategy.fireDefaultSelectionEvent(OpenStrategy.java:249)
at org.eclipse.jface.util.OpenStrategy.access$0(OpenStrategy.java:246)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:307)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1258)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3588)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3209)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2696)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2660)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2494)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:674)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:667)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
Caused by: java.lang.ClassCastException: org.eclipse.jpt.jpa.core.internal.resource.java.source.SourcePackage cannot be cast to org.eclipse.jpt.jpa.core.resource.java.JavaResourcePersistentMember
at org.eclipse.jpt.jpa.core.internal.resource.java.source.SourceAnnotation.getParent(SourceAnnotation.java:106)
at org.eclipse.jpt.jpa.core.internal.resource.java.source.SourceAnnotation.convertToStandAlone(SourceAnnotation.java:235)
at org.jboss.tools.hibernate.jpt.core.internal.resource.java.SourceGenericGeneratorsAnnotation.convertLastNestedAnnotationToStandAlone(SourceGenericGeneratorsAnnotation.java:100)
at org.eclipse.jpt.jpa.core.internal.resource.java.source.SourceAnnotatedElement.convertLastNestedAnnotation(SourceAnnotatedElement.java:288)
at org.eclipse.jpt.jpa.core.internal.resource.java.source.SourceAnnotatedElement.removeAnnotation(SourceAnnotatedElement.java:276)
at org.eclipse.jpt.jpa.core.internal.resource.java.source.SourceAnnotatedElement.removeAnnotation(SourceAnnotatedElement.java:260)
at org.jboss.tools.hibernate.jpt.core.internal.context.java.HibernateJavaGeneratorContainerImpl.removeGenericGenerator(HibernateJavaGeneratorContainerImpl.java:104)
at org.jboss.tools.hibernate.jpt.core.internal.context.java.HibernateJavaGeneratorContainerImpl.removeGenericGenerator(HibernateJavaGeneratorContainerImpl.java:99)
at org.jboss.tools.hibernate.jpt.ui.internal.mapping.details.GenericGeneratorsComposite$3.removeSelectedItems(GenericGeneratorsComposite.java:151)
at org.eclipse.jpt.common.ui.internal.widgets.AddRemovePane.removeItems(AddRemovePane.java:619)
at org.eclipse.jpt.common.ui.internal.widgets.AddRemovePane$4.run(AddRemovePane.java:405)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:135)
... 42 more