每当我尝试使用eclipse的css-editor打开css表时，我都会遇到此异常
java.lang.NullPointerException
at org.eclipse.wb.internal.css.editors.multi.SourcePage.updateSourceActions(SourcePage.java:129)
at org.eclipse.wb.internal.css.editors.multi.SourcePage.handleActiveState(SourcePage.java:63)
at org.eclipse.wb.internal.css.editors.multi.DefaultMultiMode.showPage(DefaultMultiMode.java:92)
at org.eclipse.wb.internal.css.editors.multi.MultiPagesMode.showSource(MultiPagesMode.java:49)
at org.eclipse.wb.internal.css.editors.multi.MultiPagesMode.create(MultiPagesMode.java:87)
at org.eclipse.wb.internal.css.editors.multi.MultiPageEditor.createPartControl(MultiPageEditor.java:46)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl(CompatibilityPart.java:140)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityEditor.createPartControl(CompatibilityEditor.java:99)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:321)
at sun.reflect.GeneratedMethodAccessor76.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:55)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:888)
at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:869)
at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:120)
at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:337)
at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:258)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:162)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:104)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:73)
at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:55)
at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:127)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:983)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:662)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:766)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$2(PartRenderingEngine.java:737)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$7.run(PartRenderingEngine.java:731)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:715)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl$1.handleEvent(PartServiceImpl.java:92)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler$1.run(UIEventHandler.java:40)
at org.eclipse.swt.widgets.Synchronizer.syncExec(Synchronizer.java:187)
at org.eclipse.ui.internal.UISynchronizer.syncExec(UISynchronizer.java:156)
at org.eclipse.swt.widgets.Display.syncExec(Display.java:4734)
at org.eclipse.e4.ui.internal.workbench.swt.E4Application$1.syncExec(E4Application.java:218)
at org.eclipse.e4.ui.services.internal.events.UIEventHandler.handleEvent(UIEventHandler.java:36)
at org.eclipse.equinox.internal.event.EventHandlerWrapper.handleEvent(EventHandlerWrapper.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:197)
at org.eclipse.equinox.internal.event.EventHandlerTracker.dispatchEvent(EventHandlerTracker.java:1)
at org.eclipse.osgi.framework.eventmgr.EventManager.dispatchEvent(EventManager.java:230)
at org.eclipse.osgi.framework.eventmgr.ListenerQueue.dispatchEventSynchronous(ListenerQueue.java:148)
at org.eclipse.equinox.internal.event.EventAdminImpl.dispatchEvent(EventAdminImpl.java:135)
at org.eclipse.equinox.internal.event.EventAdminImpl.sendEvent(EventAdminImpl.java:78)
at org.eclipse.equinox.internal.event.EventComponent.sendEvent(EventComponent.java:39)
at org.eclipse.e4.ui.services.internal.events.EventBroker.send(EventBroker.java:81)
at org.eclipse.e4.ui.internal.workbench.UIEventPublisher.notifyChanged(UIEventPublisher.java:59)
at org.eclipse.emf.common.notify.impl.BasicNotifierImpl.eNotify(BasicNotifierImpl.java:374)
at org.eclipse.e4.ui.model.application.ui.impl.ElementContainerImpl.setSelectedElement(ElementContainerImpl.java:171)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.showElementInWindow(ModelServiceImpl.java:488)
at org.eclipse.e4.ui.internal.workbench.ModelServiceImpl.bringToTop(ModelServiceImpl.java:454)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.delegateBringToTop(PartServiceImpl.java:692)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.bringToTop(PartServiceImpl.java:385)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.showPart(PartServiceImpl.java:1126)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3182)
at org.eclipse.ui.internal.WorkbenchPage.access$23(WorkbenchPage.java:3104)
at org.eclipse.ui.internal.WorkbenchPage$9.run(WorkbenchPage.java:3086)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3081)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3045)
at org.eclipse.ui.actions.OpenWithMenu.openEditor(OpenWithMenu.java:338)
at org.eclipse.ui.actions.OpenWithMenu$2.handleEvent(OpenWithMenu.java:180)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4353)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1061)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4172)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3761)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1151)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1032)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:148)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:636)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:579)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:135)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:382)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:236)
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:648)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:603)
at org.eclipse.equinox.launcher.Main.run(Main.java:1465)
eclipse告诉我的唯一事情是"failed to create part's controls"。谁能告诉我发生了什么？由于eclipse的这个功能以前从未奏过，我觉得在texteditor中编辑我的css真的很烦人...