While following the Ticket Monster example, I got the following error when trying to generate the JPA annotations for the Venue class (selecting the class in the project explorer, then Source>Generate JPA annotations :
java.lang.NullPointerException at org.hibernate.eclipse.jdt.ui.internal.jpa.common.Utils.findType(Utils.java:73) at org.hibernate.eclipse.jdt.ui.internal.jpa.common.Utils.findCompilationUnit(Utils.java:51) at org.hibernate.eclipse.jdt.ui.internal.jpa.common.Utils.findCompilationUnit(Utils.java:90) at org.hibernate.eclipse.jdt.ui.internal.jpa.actions.JPAMapToolActor.updateSelectedItems(JPAMapToolActor.java:273) at org.hibernate.eclipse.jdt.ui.internal.jpa.actions.JPAMapToolActor.updateSelected(JPAMapToolActor.java:109) at org.hibernate.eclipse.jdt.ui.internal.jpa.actions.JPAMapToolActionDelegate.runInternal(JPAMapToolActionDelegate.java:81) at org.hibernate.eclipse.jdt.ui.internal.jpa.actions.JPAMapToolActionDelegate.run(JPAMapToolActionDelegate.java:56) at org.eclipse.ui.internal.PluginAction.runWithEvent(PluginAction.java:253) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:595) at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:511) at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:420) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84) at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4188) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1467) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1490) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1475) at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1279) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4031) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3658) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1151) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032) at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148) at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:636) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:135) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:382) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:236) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:648) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603) at org.eclipse.equinox.launcher.Main.run(Main.java:1465)