在eclipse marketplace中下载了groovy插件，发现使用的groovy版本跟项目中使用的groovy版本不一致。
于是在Preferences -> Groovy -> Compiler中点击了版本切换（原来的groovy版本是2.4.x,我想改成2.5.x）,点击之后自动重启了eclipse
然后悲剧的事情发生了，重启之后变成了这个样子：
左边项目目录显示出现了异常，异常信息如下：
org.eclipse.core.runtime.InvalidRegistryObjectException: Invalid registry object at org.eclipse.core.internal.registry.RegistryObjectManager.basicGetObject(RegistryObjectManager.java:273) at org.eclipse.core.internal.registry.RegistryObjectManager.getObject(RegistryObjectManager.java:263) at org.eclipse.core.internal.registry.ConfigurationElementHandle.getConfigurationElement(ConfigurationElementHandle.java:26) at org.eclipse.core.internal.registry.ConfigurationElementHandle.getChildren(ConfigurationElementHandle.java:46) at org.eclipse.core.internal.adapter.AdapterFactoryProxy.getAdapterNames(AdapterFactoryProxy.java:92) at org.eclipse.core.internal.runtime.AdapterManager.addFactoriesFor(AdapterManager.java:106) at org.eclipse.core.internal.runtime.AdapterManager.getFactories(AdapterManager.java:209) at org.eclipse.core.internal.runtime.AdapterManager.getAdapter(AdapterManager.java:292) at org.eclipse.core.runtime.PlatformObject.getAdapter(PlatformObject.java:68) at org.eclipse.core.runtime.Adapters.adapt(Adapters.java:59) at org.eclipse.core.runtime.Adapters.adapt(Adapters.java:107) at org.eclipse.ui.model.WorkbenchLabelProvider.getAdapter3(WorkbenchLabelProvider.java:156) at org.eclipse.ui.model.WorkbenchLabelProvider.getStyledText(WorkbenchLabelProvider.java:204) at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.findStyledText(NavigatorContentServiceLabelProvider.java:167) at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.getStyledText(NavigatorContentServiceLabelProvider.java:153) at org.eclipse.ui.internal.navigator.NavigatorDecoratingLabelProvider$StyledLabelProviderAdapter.getStyledText(NavigatorDecoratingLabelProvider.java:63) at org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.getStyledText(DelegatingStyledCellLabelProvider.java:206) at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider.getStyledText(DecoratingStyledCellLabelProvider.java:194) at org.eclipse.ui.internal.navigator.NavigatorDecoratingLabelProvider.getText(NavigatorDecoratingLabelProvider.java:192) at org.eclipse.ui.internal.navigator.framelist.TreeFrame.<init>(TreeFrame.java:75) at org.eclipse.ui.internal.navigator.framelist.TreeViewerFrameSource.createFrame(TreeViewerFrameSource.java:60) at org.eclipse.ui.internal.navigator.CommonNavigatorFrameSource.createFrame(CommonNavigatorFrameSource.java:41) at org.eclipse.ui.internal.navigator.framelist.TreeViewerFrameSource.getCurrentFrame(TreeViewerFrameSource.java:85) at org.eclipse.ui.internal.navigator.framelist.TreeViewerFrameSource.getFrame(TreeViewerFrameSource.java:97) at org.eclipse.ui.internal.navigator.framelist.FrameList.init(FrameList.java:166) at org.eclipse.ui.internal.navigator.framelist.FrameList.<init>(FrameList.java:55) at org.eclipse.ui.navigator.CommonViewer.createFrameList(CommonViewer.java:539) at org.eclipse.ui.navigator.CommonNavigator.createPartControl(CommonNavigator.java:215) at org.eclipse.ui.navigator.resources.ProjectExplorer.createPartControl(ProjectExplorer.java:88) at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.createPartControl(CompatibilityPart.java:151) at org.eclipse.ui.internal.e4.compatibility.CompatibilityView.createPartControl(CompatibilityView.java:147) at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.create(CompatibilityPart.java:355) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.eclipse.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:55) at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:990) at org.eclipse.e4.core.internal.di.InjectorImpl.processAnnotated(InjectorImpl.java:955) at org.eclipse.e4.core.internal.di.InjectorImpl.inject(InjectorImpl.java:124) at org.eclipse.e4.core.internal.di.InjectorImpl.internalMake(InjectorImpl.java:399) at org.eclipse.e4.core.internal.di.InjectorImpl.make(InjectorImpl.java:318) at org.eclipse.e4.core.contexts.ContextInjectionFactory.make(ContextInjectionFactory.java:162) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.createFromBundle(ReflectionContributionFactory.java:105) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.doCreate(ReflectionContributionFactory.java:74) at org.eclipse.e4.ui.internal.workbench.ReflectionContributionFactory.create(ReflectionContributionFactory.java:56) at org.eclipse.e4.ui.workbench.renderers.swt.ContributedPartRenderer.createWidget(ContributedPartRenderer.java:129) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:997) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:666) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$1.run(PartRenderingEngine.java:551) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:535) at org.eclipse.e4.ui.workbench.renderers.swt.ElementReferenceRenderer.createWidget(ElementReferenceRenderer.java:70) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createWidget(PartRenderingEngine.java:997) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:666) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.StackRenderer.showTab(StackRenderer.java:1289) at org.eclipse.e4.ui.workbench.renderers.swt.LazyStackRenderer.postProcess(LazyStackRenderer.java:97) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:684) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:69) at org.eclipse.e4.ui.workbench.renderers.swt.SashRenderer.processContents(SashRenderer.java:137) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:680) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:69) at org.eclipse.e4.ui.workbench.renderers.swt.PerspectiveRenderer.processContents(PerspectiveRenderer.java:49) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:680) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.PerspectiveStackRenderer.showTab(PerspectiveStackRenderer.java:79) at org.eclipse.e4.ui.workbench.renderers.swt.LazyStackRenderer.postProcess(LazyStackRenderer.java:97) at org.eclipse.e4.ui.workbench.renderers.swt.PerspectiveStackRenderer.postProcess(PerspectiveStackRenderer.java:61) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:684) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:69) at org.eclipse.e4.ui.workbench.renderers.swt.SashRenderer.processContents(SashRenderer.java:137) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:680) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.workbench.renderers.swt.SWTPartRenderer.processContents(SWTPartRenderer.java:69) at org.eclipse.e4.ui.workbench.renderers.swt.WBWRenderer.processContents(WBWRenderer.java:704) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:680) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.safeCreateGui(PartRenderingEngine.java:772) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.access$0(PartRenderingEngine.java:743) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$2.run(PartRenderingEngine.java:737) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.createGui(PartRenderingEngine.java:721) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1081) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336) at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1044) at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153) at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:680) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:594) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:151) 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:388) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:653) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:590) at org.eclipse.equinox.launcher.Main.run(Main.java:1499)
然后在网上找到了github上的一篇issue：https://github.com/groovy/groovy-eclipse/issues/317，里面一些提出了一些解决办法。
之后我发现eclipse中的groovy插件不是最新版本，于是更新了groovy插件，并切换groovy版本到2.6.x，重启了eclipse，错误消失了。
当我切换到2.4.x，错误是还会出现这样的错误。