bad version in .class file

2008-07-20T18:09:23Z

occurs when i try to access the preference page.

eclipse.buildId=I20080617-2000
java.version=1.5.0_13
java.vendor=Apple Inc.
BootLoader constants: OS=macosx, ARCH=x86, WS=carbon, NL=en_US
Framework arguments: -keyring /Users/jae/.eclipse_keyring -showlocation
Command-line arguments: -os macosx -ws carbon -arch x86 -keyring /Users/jae/.eclipse_keyring -consoleLog -showlocation

Error
Sun Jul 20 14:05:49 EDT 2008
Unable to create the selected preference page.

java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.defineClass(DefaultClassLoader.java:165)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.defineClass(ClasspathManager.java:554)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findClassImpl(ClasspathManager.java:524)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClassImpl(ClasspathManager.java:455)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass_LockClassLoader(ClasspathManager.java:443)
at org.eclipse.osgi.baseadaptor.loader.ClasspathManager.findLocalClass(ClasspathManager.java:423)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.findLocalClass(DefaultClassLoader.java:193)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findLocalClass(BundleLoader.java:368)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findClassInternal(BundleLoader.java:444)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.java:397)
at org.eclipse.osgi.framework.internal.core.BundleLoader.findClass(BundleLoader.java:385)
at org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader.loadClass(DefaultClassLoader.java:87)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at org.eclipse.osgi.framework.internal.core.BundleLoader.loadClass(BundleLoader.java:313)
at org.eclipse.osgi.framework.internal.core.BundleHost.loadClass(BundleHost.java:227)
at org.eclipse.osgi.framework.internal.core.AbstractBundle.loadClass(AbstractBundle.java:1274)
at org.eclipse.core.internal.registry.osgi.RegistryStrategyOSGI.createExecutableExtension(RegistryStrategyOSGI.java:160)
at org.eclipse.core.internal.registry.ExtensionRegistry.createExecutableExtension(ExtensionRegistry.java:867)
at org.eclipse.core.internal.registry.ConfigurationElement.createExecutableExtension(ConfigurationElement.java:243)
at org.eclipse.core.internal.registry.ConfigurationElementHandle.createExecutableExtension(ConfigurationElementHandle.java:51)
at org.eclipse.ui.internal.WorkbenchPlugin$1.run(WorkbenchPlugin.java:267)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPlugin.createExtension(WorkbenchPlugin.java:263)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceNode.createPage(WorkbenchPreferenceNode.java:47)
at org.eclipse.jface.preference.PreferenceDialog.createPage(PreferenceDialog.java:1304)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.createPage(FilteredPreferenceDialog.java:369)
at org.eclipse.jface.preference.PreferenceDialog.showPage(PreferenceDialog.java:1195)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.showPage(FilteredPreferenceDialog.java:570)
at org.eclipse.jface.preference.PreferenceDialog$10.run(PreferenceDialog.java:700)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog$9.selectionChanged(PreferenceDialog.java:696)
at org.eclipse.jface.viewers.StructuredViewer$3.run(StructuredViewer.java:842)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:880)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)
at org.eclipse.jface.viewers.StructuredViewer.firePostSelectionChanged(StructuredViewer.java:840)
at org.eclipse.jface.viewers.StructuredViewer.setSelection(StructuredViewer.java:1639)
at org.eclipse.jface.viewers.TreeViewer.setSelection(TreeViewer.java:1104)
at org.eclipse.jface.preference.PreferenceDialog.selectSavedItem(PreferenceDialog.java:1019)
at org.eclipse.ui.internal.dialogs.FilteredPreferenceDialog.selectSavedItem(FilteredPreferenceDialog.java:624)
at org.eclipse.jface.preference.PreferenceDialog$4.run(PreferenceDialog.java:369)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.jface.preference.PreferenceDialog.createContents(PreferenceDialog.java:365)
at org.eclipse.jface.window.Window.create(Window.java:431)
at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1089)
at org.eclipse.ui.internal.dialogs.WorkbenchPreferenceDialog.createDialogOn(WorkbenchPreferenceDialog.java:96)
at org.eclipse.ui.dialogs.PreferencesUtil.createPreferenceDialogOn(PreferencesUtil.java:97)
at org.eclipse.ui.internal.OpenPreferencesAction.run(OpenPreferencesAction.java:64)
at org.eclipse.ui.internal.carbon.CarbonUIEnhancer.runAction(CarbonUIEnhancer.java:381)
at org.eclipse.ui.internal.carbon.CarbonUIEnhancer.access$1(CarbonUIEnhancer.java:375)
at org.eclipse.ui.internal.carbon.CarbonUIEnhancer$Target.commandProc(CarbonUIEnhancer.java:110)
at org.eclipse.swt.internal.carbon.OS.SendEventToEventTarget(Native Method)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3047)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2382)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2346)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2198)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:493)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:488)
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:193)
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:382)
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:585)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:549)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:504)
at org.eclipse.equinox.launcher.Main.run(Main.java:1236)

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bad version in .class file