Eclipse, problème avec les class

Bonjour,
je voudrais essayer d'ouvrir les .class avec eclipse, normalement cela est supposé fonctionner sauf que sa m'affiche:

Could not open the editor: The Class File Viewer cannot handle the given input

Détails:

org.eclipse.core.runtime.CoreException: The Class File Viewer cannot handle the given input ('org.eclipse.ui.ide.FileStoreEditorInput').
	at org.eclipse.jdt.internal.ui.javaeditor.ClassFileEditor.doSetInput(ClassFileEditor.java:642)
	at org.eclipse.ui.texteditor.AbstractTextEditor$19.run(AbstractTextEditor.java:3116)
	at org.eclipse.jface.operation.ModalContext.runInCurrentThread(ModalContext.java:464)
	at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:372)
	at org.eclipse.jface.window.ApplicationWindow$1.run(ApplicationWindow.java:759)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
	at org.eclipse.jface.window.ApplicationWindow.run(ApplicationWindow.java:756)
	at org.eclipse.ui.internal.WorkbenchWindow.run(WorkbenchWindow.java:2579)
	at org.eclipse.ui.texteditor.AbstractTextEditor.internalInit(AbstractTextEditor.java:3134)
	at org.eclipse.ui.texteditor.AbstractTextEditor.init(AbstractTextEditor.java:3161)
	at org.eclipse.ui.internal.EditorManager.createSite(EditorManager.java:798)
	at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:644)
	at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:462)
	at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
	at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:313)
	at org.eclipse.ui.internal.presentations.PresentablePart.setVisible(PresentablePart.java:180)
	at org.eclipse.ui.internal.presentations.util.PresentablePartFolder.select(PresentablePartFolder.java:270)
	at org.eclipse.ui.internal.presentations.util.LeftToRightTabOrder.select(LeftToRightTabOrder.java:65)
	at org.eclipse.ui.internal.presentations.util.TabbedStackPresentation.selectPart(TabbedStackPresentation.java:473)
	at org.eclipse.ui.internal.PartStack.refreshPresentationSelection(PartStack.java:1256)
	at org.eclipse.ui.internal.PartStack.setSelection(PartStack.java:1209)
	at org.eclipse.ui.internal.PartStack.showPart(PartStack.java:1608)
	at org.eclipse.ui.internal.PartStack.add(PartStack.java:499)
	at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:103)
	at org.eclipse.ui.internal.PartStack.add(PartStack.java:485)
	at org.eclipse.ui.internal.EditorStack.add(EditorStack.java:112)
	at org.eclipse.ui.internal.EditorSashContainer.addEditor(EditorSashContainer.java:63)
	at org.eclipse.ui.internal.EditorAreaHelper.addToLayout(EditorAreaHelper.java:225)
	at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:213)
	at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:778)
	at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:677)
	at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:638)
	at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2854)
	at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2762)
	at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2754)
	at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2705)
	at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2701)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2685)
	at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2668)
	at org.eclipse.ui.ide.IDE.openEditorOnFileStore(IDE.java:1151)
	at org.eclipse.ui.internal.ide.actions.OpenLocalFileAction.run(OpenLocalFileAction.java:107)
	at org.eclipse.ui.internal.ide.actions.OpenLocalFileAction.run(OpenLocalFileAction.java:76)
	at org.eclipse.ui.internal.PluginAction.runWithEvent(PluginAction.java:251)
	at org.eclipse.ui.internal.WWinPluginAction.runWithEvent(WWinPluginAction.java:229)
	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:1176)
	at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3493)
	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3112)
	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:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:616)
	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)

Est-ce que quelqu'un sait comment ?
Merci d'avance !

P.S. J'ai chercher sur google mais je n'ai pas trouvé, ou je n'ai pas bien cherché.