What steps will reproduce the problem?
1. create enum and a class with the enum's field
2. create a new hbm file wizard for the class
3. choose next and finish.

– Error Details –
Date: Wed Mar 10 13:15:41 GMT 2010
Message: Unhandled event loop exception
Severity: Error
Product: Eclipse SDK 3.5.2.v201002111343 (org.eclipse.sdk.ide)
Plugin: org.eclipse.ui
Session Data:
eclipse.buildId=M20100211-1343
java.version=1.6.0_18
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=iw_IL
Framework arguments: showsplash org.eclipse.platform -showlocation
Command-line arguments: -os win32 -ws win32 -arch x86 showsplash org.eclipse.platform -data c:\Workdir\clientworkspace\applications\ -showlocation -debug

Exception Stack Trace:
java.lang.NullPointerException
at org.hibernate.eclipse.jdt.ui.wizards.TypeVisitor.visit(ConfigurationActor.java:582)
at org.eclipse.jdt.core.dom.SimpleType.accept0(SimpleType.java:135)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2480)
at org.hibernate.eclipse.jdt.ui.wizards.ProcessEntityInfo.createProperty(ConfigurationActor.java:400)
at org.hibernate.eclipse.jdt.ui.wizards.ProcessEntityInfo.createProperty(ConfigurationActor.java:395)
at org.hibernate.eclipse.jdt.ui.wizards.ProcessEntityInfo.visit(ConfigurationActor.java:347)
at org.eclipse.jdt.core.dom.FieldDeclaration.accept0(FieldDeclaration.java:279)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2480)
at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2551)
at org.eclipse.jdt.core.dom.TypeDeclaration.accept0(TypeDeclaration.java:484)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2480)
at org.eclipse.jdt.core.dom.ASTNode.acceptChildren(ASTNode.java:2551)
at org.eclipse.jdt.core.dom.CompilationUnit.accept0(CompilationUnit.java:219)
at org.eclipse.jdt.core.dom.ASTNode.accept(ASTNode.java:2480)
at org.hibernate.eclipse.jdt.ui.wizards.ConfigurationActor.createConfiguration(ConfigurationActor.java:144)
at org.hibernate.eclipse.jdt.ui.wizards.ConfigurationActor.createConfigurations(ConfigurationActor.java:125)
at org.hibernate.eclipse.jdt.ui.wizards.NewHibernateMappingFileWizard.createConfigurations(NewHibernateMappingFileWizard.java:530)
at org.hibernate.eclipse.jdt.ui.wizards.NewHibernateMappingFileWizard.getPlaces2Gen(NewHibernateMappingFileWizard.java:287)
at org.hibernate.eclipse.jdt.ui.wizards.NewHibernateMappingFileWizard.performFinish(NewHibernateMappingFileWizard.java:362)
at org.eclipse.jface.wizard.WizardDialog.finishPressed(WizardDialog.java:752)
at org.eclipse.jface.wizard.WizardDialog.buttonPressed(WizardDialog.java:373)
at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:228)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3910)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3503)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
at org.eclipse.jface.window.Window.open(Window.java:801)
at org.eclipse.ui.internal.handlers.WizardHandler$New.executeHandler(WizardHandler.java:253)
at org.eclipse.ui.internal.handlers.WizardHandler.execute(WizardHandler.java:273)
at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:294)
at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
at org.eclipse.ui.internal.actions.CommandAction.runWithEvent(CommandAction.java:157)
at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3910)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3503)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:500)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:493)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:194)
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:368)
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:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:1311)