Error opening a view

Here my error. Any idea ??

java.lang.NullPointerException
at java.lang.String.compareTo(String.java:1167)
at com.webmethods.caf.faces.designtime.ui.jsfview.palette.JsfViewPaletteFactory$1.compare(JsfViewPaletteFactory.java:471)
at java.util.Arrays.mergeSort(Arrays.java:1270)
at java.util.Arrays.mergeSort(Arrays.java:1281)
at java.util.Arrays.mergeSort(Arrays.java:1281)
at java.util.Arrays.mergeSort(Arrays.java:1282)
at java.util.Arrays.mergeSort(Arrays.java:1281)
at java.util.Arrays.sort(Arrays.java:1210)
at java.util.Collections.sort(Collections.java:159)
at com.webmethods.caf.faces.designtime.ui.jsfview.palette.JsfViewPaletteFactory.sortPaletteContainerChildren(JsfViewPaletteFactory.java:454)
at com.webmethods.caf.faces.designtime.ui.jsfview.palette.JsfViewPaletteFactory.sortPaletteContainerChildren(JsfViewPaletteFactory.java:480)
at com.webmethods.caf.faces.designtime.ui.jsfview.palette.JsfViewPaletteFactory.initializePalette(JsfViewPaletteFactory.java:413)
at com.webmethods.caf.faces.designtime.ui.jsfview.palette.JsfViewPaletteFactory.initializePalette(JsfViewPaletteFactory.java:171)
at com.webmethods.caf.faces.pagedesigner.PortletPageGraphicalEditor.setInput(PortletPageGraphicalEditor.java:532)
at org.eclipse.gef.ui.parts.GraphicalEditor.init(GraphicalEditor.java:318)
at org.eclipse.ui.part.MultiPageEditorPart.addPage(MultiPageEditorPart.java:213)
at org.eclipse.ui.part.MultiPageEditorPart.addPage(MultiPageEditorPart.java:187)
at com.webmethods.caf.faces.pagedesigner.PortletPageDesigner.createAndAddDesignPage(PortletPageDesigner.java:109)
at com.webmethods.caf.faces.pagedesigner.PortletPageDesigner.createPages(PortletPageDesigner.java:46)
at org.eclipse.ui.part.MultiPageEditorPart.createPartControl(MultiPageEditorPart.java:310)
at org.eclipse.ui.internal.EditorReference.createPartHelper(EditorReference.java:661)
at org.eclipse.ui.internal.EditorReference.createPart(EditorReference.java:428)
at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:594)
at org.eclipse.ui.internal.PartPane.setVisible(PartPane.java:306)
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:217)
at org.eclipse.ui.internal.EditorAreaHelper.addEditor(EditorAreaHelper.java:207)
at org.eclipse.ui.internal.EditorManager.createEditorTab(EditorManager.java:779)
at org.eclipse.ui.internal.EditorManager.openEditorFromDescriptor(EditorManager.java:678)
at org.eclipse.ui.internal.EditorManager.openEditor(EditorManager.java:639)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditorBatched(WorkbenchPage.java:2817)
at org.eclipse.ui.internal.WorkbenchPage.busyOpenEditor(WorkbenchPage.java:2729)
at org.eclipse.ui.internal.WorkbenchPage.access$11(WorkbenchPage.java:2721)
at org.eclipse.ui.internal.WorkbenchPage$10.run(WorkbenchPage.java:2673)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2668)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2652)
at org.eclipse.ui.internal.WorkbenchPage.openEditor(WorkbenchPage.java:2643)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:646)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:605)
at org.eclipse.ui.ide.IDE.openEditor(IDE.java:1100)
at org.eclipse.ui.internal.views.markers.ExtendedMarkersView.openMarkerInEditor(ExtendedMarkersView.java:253)
at org.eclipse.ui.internal.views.markers.ExtendedMarkersView.openSelectedMarkers(ExtendedMarkersView.java:1494)
at org.eclipse.ui.internal.views.markers.ExtendedMarkersView$3.open(ExtendedMarkersView.java:517)
at org.eclipse.jface.viewers.StructuredViewer$2.run(StructuredViewer.java:820)
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.fireOpen(StructuredViewer.java:818)
at org.eclipse.jface.viewers.StructuredViewer.handleOpen(StructuredViewer.java:1079)
at org.eclipse.jface.viewers.StructuredViewer$6.handleOpen(StructuredViewer.java:1183)
at org.eclipse.jface.util.OpenStrategy.fireOpenEvent(OpenStrategy.java:263)
at org.eclipse.jface.util.OpenStrategy.access$2(OpenStrategy.java:257)
at org.eclipse.jface.util.OpenStrategy$1.handleEvent(OpenStrategy.java:297)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1003)
at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3823)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3422)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2384)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2348)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2200)
at org.eclipse.ui.internal.Workbench$5.run(Workbench.java:495)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:288)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:490)
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:386)
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:597)
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)
at org.eclipse.equinox.launcher.Main.main(Main.java:1212)