#39 'Run configuration' not working with Eclipse 3.6

[Anonymous]

When I try to configure the run configuration with "Run->Run Configurations" I get an Eclipse runtime problem (se below).
I think the class WorkingDirectoryBlock is missing in Eclipse since Ganymede.

java.lang.NoClassDefFoundError: org/eclipse/jdt/internal/debug/ui/launcher/WorkingDirectoryBlock
at com.evelopers.unimod.plugin.eclipse.launch.UniModInterpreterTabGroup.createTabs(UniModInterpreterTabGroup.java:29)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupWrapper.createTabs(LaunchConfigurationTabGroupWrapper.java:137)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer$9.run(LaunchConfigurationTabGroupViewer.java:864)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.createGroup(LaunchConfigurationTabGroupViewer.java:873)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.showInstanceTabsFor(LaunchConfigurationTabGroupViewer.java:779)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.displayInstanceTabs(LaunchConfigurationTabGroupViewer.java:735)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer$8.run(LaunchConfigurationTabGroupViewer.java:623)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.inputChanged(LaunchConfigurationTabGroupViewer.java:640)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.setInput0(LaunchConfigurationTabGroupViewer.java:602)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationTabGroupViewer.setInput(LaunchConfigurationTabGroupViewer.java:578)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.handleLaunchConfigurationSelectionChanged(LaunchConfigurationsDialog.java:940)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog$3.selectionChanged(LaunchConfigurationsDialog.java:559)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:867)
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.firePostSelectionChanged(StructuredViewer.java:865)
at org.eclipse.jface.viewers.StructuredViewer.setSelection(StructuredViewer.java:1700)
at org.eclipse.jface.viewers.TreeViewer.setSelection(TreeViewer.java:1139)
at org.eclipse.jface.viewers.Viewer.setSelection(Viewer.java:392)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.doInitialTreeSelection(LaunchConfigurationsDialog.java:599)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.initializeContent(LaunchConfigurationsDialog.java:1078)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.createContents(LaunchConfigurationsDialog.java:440)
at org.eclipse.jface.window.Window.create(Window.java:431)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.create(LaunchConfigurationsDialog.java:371)
at org.eclipse.jface.window.Window.open(Window.java:790)
at org.eclipse.debug.internal.ui.launchConfigurations.LaunchConfigurationsDialog.open(LaunchConfigurationsDialog.java:1134)
at org.eclipse.debug.ui.DebugUITools$1.run(DebugUITools.java:398)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.debug.ui.DebugUITools.openLaunchConfigurationDialogOnGroup(DebugUITools.java:406)
at org.eclipse.debug.ui.DebugUITools.openLaunchConfigurationDialogOnGroup(DebugUITools.java:340)
at org.eclipse.debug.ui.actions.OpenLaunchDialogAction.run(OpenLaunchDialogAction.java:81)
at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
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:1053)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4066)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3657)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2640)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2604)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2438)
at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:671)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:664)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)
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:369)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
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:620)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:575)
at org.eclipse.equinox.launcher.Main.run(Main.java:1408)
Caused by: java.lang.ClassNotFoundException: org.eclipse.jdt.internal.debug.ui.launcher.WorkingDirectoryBlock
at org.eclipse.osgi.internal.loader.BundleLoader.findClassInternal(BundleLoader.java:506)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:422)
at org.eclipse.osgi.internal.loader.BundleLoader.findClass(BundleLoader.java:410)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:107)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 63 more

eclipse.buildId=M20110210-1200
java.version=1.6.0_24
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=de_DE
Framework arguments: -product org.eclipse.epp.package.jee.product
Command-line arguments: -os win32 -ws win32 -arch x86 -product org.eclipse.epp.package.jee.product