We see a problem on JunoM7 with our existing JPA projects (the problem does not occur with Eclipse 3.7.sr2).
When the projects are checked out from Subversion, we get the below exceptions - and a modal error dialog.
I first filed it as an issue against JPA (see here), because there is no mention of JbossTools in the stack trace.
But they pointed a finger at your plugin.
So I tried reproducing the problem in a clean Juno7 installation (no custom plugins). And couldn't.
I then added the JBoss Hibernate plugin, and switched the JPA platform to Hibernate. And got the error again.
So I have to concur with the JPA folks. The problem appears to be triggered by JbossTools Hibernate, somehow.
Hope you can find the cause.
Thanks,
Jesper
!ENTRY org.eclipse.jface 4 0 2012-05-23 08:41:02.641
!MESSAGE java.lang.RuntimeException: java.lang.NoClassDefFoundError: org/eclipse/jpt/jpa/core/JpaAnnotationProvider
!STACK 0
java.lang.RuntimeException: java.lang.NoClassDefFoundError: org/eclipse/jpt/jpa/core/JpaAnnotationProvider
at org.eclipse.jpt.common.ui.internal.properties.JptProjectPropertiesPage.performOk(JptProjectPropertiesPage.java:258)
at org.eclipse.jface.preference.PreferenceDialog$13.run(PreferenceDialog.java:965)
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.preference.PreferenceDialog.okPressed(PreferenceDialog.java:945)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.okPressed(FilteredPreferenceDialog.java:448)
at org.eclipse.jface.preference.PreferenceDialog.buttonPressed(PreferenceDialog.java:233)
at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:624)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4169)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3758)
at org.eclipse.jface.window.Window.runEventLoop(Window.java:825)
at org.eclipse.jface.window.Window.open(Window.java:801)
at org.eclipse.ui.dialogs.PropertyDialogAction.run(PropertyDialogAction.java:158)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
at org.eclipse.jface.commands.ActionHandler.execute(ActionHandler.java:119)
at org.eclipse.ui.internal.handlers.E4HandlerProxy.execute(E4HandlerProxy.java:76)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:229)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:210)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:131)
at org.eclipse.e4.core.commands.internal.HandlerServiceImpl.executeHandler(HandlerServiceImpl.java:171)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher.executeCommand(KeyBindingDispatcher.java:276)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher.press(KeyBindingDispatcher.java:494)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher.processKeyEvent(KeyBindingDispatcher.java:545)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher.filterKeySequenceBindings(KeyBindingDispatcher.java:366)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher.access$0(KeyBindingDispatcher.java:313)
at org.eclipse.e4.ui.bindings.keys.KeyBindingDispatcher$KeyDownFilter.handleEvent(KeyBindingDispatcher.java:82)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.filterEvent(Display.java:1262)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1052)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1104)
at org.eclipse.swt.widgets.Widget.sendKeyEvent(Widget.java:1100)
at org.eclipse.swt.widgets.Widget.wmSysChar(Widget.java:2448)
at org.eclipse.swt.widgets.Control.WM_SYSCHAR(Control.java:5179)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4604)
at org.eclipse.swt.widgets.Tree.windowProc(Tree.java:5958)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4976)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2545)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3756)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1017)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:911)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:86)
at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:582)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:537)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
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:353)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:180)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:629)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:584)
at org.eclipse.equinox.launcher.Main.run(Main.java:1438)
Caused by: java.lang.NoClassDefFoundError: org/eclipse/jpt/jpa/core/JpaAnnotationProvider
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
at java.lang.Class.getConstructor0(Unknown Source)
at java.lang.Class.newInstance0(Unknown Source)
at java.lang.Class.newInstance(Unknown Source)
at org.eclipse.jpt.common.core.internal.utility.XPointTools.instantiate(XPointTools.java:46)
at org.eclipse.jpt.common.core.internal.utility.XPointTools.instantiate(XPointTools.java:38)
at org.eclipse.jpt.jpa.core.internal.platform.JpaPlatformDescriptionImpl.buildJpaPlatform(JpaPlatformDescriptionImpl.java:99)
at org.eclipse.jpt.jpa.core.internal.platform.JpaPlatformManagerImpl.buildJpaPlatformImplementation(JpaPlatformManagerImpl.java:236)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.buildJpaProjectConfig(InternalJpaProjectManager.java:627)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.buildJpaProject(InternalJpaProjectManager.java:601)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.addJpaProject(InternalJpaProjectManager.java:582)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.rebuildJpaProject_(InternalJpaProjectManager.java:515)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager$RebuildJpaProjectCommand.execute(InternalJpaProjectManager.java:504)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.waitToExecute(InternalJpaProjectManager.java:926)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.waitToExecute(InternalJpaProjectManager.java:906)
at org.eclipse.jpt.jpa.core.internal.InternalJpaProjectManager.rebuildJpaProject(InternalJpaProjectManager.java:491)
at org.eclipse.jpt.jpa.core.internal.ProjectAdapterFactory$JpaProjectReference.rebuild(ProjectAdapterFactory.java:108)
at org.eclipse.jpt.jpa.ui.internal.properties.JpaProjectPropertiesPage.rebuildProject_(JpaProjectPropertiesPage.java:842)
at org.eclipse.jpt.jpa.ui.internal.properties.JpaProjectPropertiesPage.rebuildProject(JpaProjectPropertiesPage.java:835)
at org.eclipse.jpt.common.ui.internal.properties.JptProjectPropertiesPage.performOk_(JptProjectPropertiesPage.java:317)
at org.eclipse.jpt.common.ui.internal.properties.JptProjectPropertiesPage$OkRunnableWithProgress$OkWorkspaceRunnable.run(JptProjectPropertiesPage.java:300)
at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:2344)
at org.eclipse.jpt.common.ui.internal.properties.JptProjectPropertiesPage$OkRunnableWithProgress.run(JptProjectPropertiesPage.java:280)
at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:121)
Caused by: java.lang.ClassNotFoundException: org.eclipse.jpt.jpa.core.JpaAnnotationProvider
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:501)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:421)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:412)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 25 more