After i have added JSF capabilities to my project. i switched to "Web Projects" view and i get an error :

java.lang.NullPointerException
at org.eclipse.core.runtime.Path.isPrefixOf(Path.java:634)
at org.jboss.tools.common.model.util.EclipseResourceUtil.findResourceInFileSystem(EclipseResourceUtil.java:361)
at org.jboss.tools.common.model.util.EclipseResourceUtil.getObjectByResource(EclipseResourceUtil.java:106)
at org.jboss.tools.common.model.util.EclipseResourceUtil.createObjectForResource(EclipseResourceUtil.java:282)
at org.jboss.tools.common.model.markers.XMarkerManager.reload(XMarkerManager.java:62)
at org.jboss.tools.common.model.markers.XMarkerManager.reload(XMarkerManager.java:53)
at org.jboss.tools.common.model.markers.XMarkerManager.<init>(XMarkerManager.java:37)
at org.jboss.tools.common.model.markers.XMarkerManager.getInstance(XMarkerManager.java:28)
at org.jboss.tools.common.model.ui.navigator.LabelDecoratorImpl.getErrorState(LabelDecoratorImpl.java:71)
at org.jboss.tools.common.model.ui.navigator.LabelDecoratorImpl.decorateImage(LabelDecoratorImpl.java:40)
at org.eclipse.jface.viewers.DecoratingLabelProvider.getImage(DecoratingLabelProvider.java:94)
at org.eclipse.jface.viewers.DecoratingLabelProvider.updateLabel(DecoratingLabelProvider.java:356)
at org.eclipse.jface.viewers.WrappedViewerLabelProvider.update(WrappedViewerLabelProvider.java:183)
at org.eclipse.jface.viewers.ViewerColumn.refresh(ViewerColumn.java:135)
at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:911)
at org.eclipse.jface.viewers.AbstractTreeViewer$UpdateItemSafeRunnable.run(AbstractTreeViewer.java:97)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:857)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:46)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:199)
at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:991)
at org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run(StructuredViewer.java:466)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.core.runtime.Platform.run(Platform.java:857)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:46)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:199)
at org.eclipse.jface.viewers.StructuredViewer.updateItem(StructuredViewer.java:2026)
at org.eclipse.jface.viewers.AbstractTreeViewer.createTreeItem(AbstractTreeViewer.java:806)
at org.eclipse.jface.viewers.AbstractTreeViewer$1.run(AbstractTreeViewer.java:781)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
at org.eclipse.jface.viewers.AbstractTreeViewer.createChildren(AbstractTreeViewer.java:755)
at org.eclipse.jface.viewers.TreeViewer.createChildren(TreeViewer.java:627)
at org.eclipse.jface.viewers.AbstractTreeViewer.handleTreeExpand(AbstractTreeViewer.java:1410)
at org.eclipse.jface.viewers.TreeViewer.handleTreeExpand(TreeViewer.java:918)
at org.eclipse.jface.viewers.AbstractTreeViewer$4.treeExpanded(AbstractTreeViewer.java:1421)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:125)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:962)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:947)
at org.eclipse.swt.widgets.Tree.wmNotifyChild(Tree.java:7053)
at org.eclipse.swt.widgets.Control.wmNotify(Control.java:4563)
at org.eclipse.swt.widgets.Composite.wmNotify(Composite.java:1581)
at org.eclipse.swt.widgets.Control.WM_NOTIFY(Control.java:4216)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3724)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4351)
at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2179)
at org.eclipse.swt.widgets.Tree.callWindowProc(Tree.java:1541)
at org.eclipse.swt.widgets.Tree.WM_LBUTTONDOWN(Tree.java:5798)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3705)
at org.eclipse.swt.widgets.Tree.windowProc(Tree.java:5370)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4364)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:2265)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3291)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353)
at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219)
at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466)
at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176)
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:508)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447)
at org.eclipse.equinox.launcher.Main.run(Main.java:1173)
at org.eclipse.equinox.launcher.Main.main(Main.java:1148)