maven - eclipse打开xml出错

eclipse版本eclipse-jee-kepler-SR2 4.3
maven插件是eclipse自带的，
创建了一个maven项目，mop.xml用maven mop editor打开时，出现以下错误，

Error
Sun Oct 11 09:40:58 CST 2015
Error setting focus to : org.eclipse.e4.ui.model.application.ui.basic.impl.PartImpl null

java.lang.NullPointerException

at org.eclipse.ui.forms.editor.FormEditor.getActivePageInstance(FormEditor.java:588)
at org.eclipse.m2e.editor.pom.MavenPomEditor.pageChange(MavenPomEditor.java:406)
at org.eclipse.ui.part.MultiPageEditorPart$2.widgetSelected(MultiPageEditorPart.java:292)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:248)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1081)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1066)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:778)
at org.eclipse.swt.custom.CTabFolder.setSelection(CTabFolder.java:3080)
at org.eclipse.swt.custom.CTabFolder.onFocus(CTabFolder.java:1631)
at org.eclipse.swt.custom.CTabFolder$1.handleEvent(CTabFolder.java:274)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1057)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1081)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1062)
at org.eclipse.swt.widgets.Control.sendFocusEvent(Control.java:2842)
at org.eclipse.swt.widgets.Widget.wmSetFocus(Widget.java:2421)
at org.eclipse.swt.widgets.Control.WM_SETFOCUS(Control.java:5235)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:4681)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4977)
at org.eclipse.swt.internal.win32.OS.SetFocus(Native Method)
at org.eclipse.swt.widgets.Control.forceFocus(Control.java:1098)
at org.eclipse.swt.widgets.Control.setFocus(Control.java:3323)
at org.eclipse.swt.widgets.Composite.setFocus(Composite.java:1042)
at org.eclipse.swt.custom.CTabFolder.setFocus(CTabFolder.java:2531)
at org.eclipse.swt.widgets.Composite.setFocus(Composite.java:1040)
at org.eclipse.ui.internal.ErrorEditorPart.setFocus(ErrorEditorPart.java:110)
at org.eclipse.ui.internal.e4.compatibility.CompatibilityPart.delegateSetFocus(CompatibilityPart.java:192)
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.e4.core.internal.di.MethodRequestor.execute(MethodRequestor.java:56)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:243)
at org.eclipse.e4.core.internal.di.InjectorImpl.invokeUsingClass(InjectorImpl.java:249)
at org.eclipse.e4.core.internal.di.InjectorImpl.invoke(InjectorImpl.java:220)
at org.eclipse.e4.core.contexts.ContextInjectionFactory.invoke(ContextInjectionFactory.java:107)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.focusGui(PartRenderingEngine.java:763)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:606)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:553)
at org.eclipse.e4.ui.internal.workbench.PartServiceImpl.activate(PartServiceImpl.java:542)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:3120)
at org.eclipse.ui.internal.WorkbenchPage.access$21(WorkbenchPage.java:3034)
at org.eclipse.ui.internal.WorkbenchPage$8.run(WorkbenchPage.java:3016)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:3012)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2976)
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.Widget.sendEvent(Widget.java:1057)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4170)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3759)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$9.run(PartRenderingEngine.java:1113)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:997)
at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:140)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:611)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:567)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:150)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:124)
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:354)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:181)
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:636)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:591)
at org.eclipse.equinox.launcher.Main.run(Main.java:1450)
at org.eclipse.equinox.launcher.Main.main(Main.java:1426)

大家遇到过这个问题没，请帮心解决一下，谢谢！