Hi
I am trying to create a simple JSF application. I followed all the guidelines and downloaded JSF1.2(Apache Myfaces JSf core -1.2 API 1.2.9). when I clicked
on web.xml or faces-config.xml file , getting the following error

java.lang.NoClassDefFoundError: org/jboss/tools/common/model/ui/attribute/adapter/XChildrenTableStructuredAdapter$DefaultTableLabelP rovider
at org.jboss.tools.common.model.ui.attribute.adapter. XChildrenTableStructuredAdapter.<init>(XChildrenTa bleStructuredAdapter.java:754)
at org.jboss.tools.common.model.ui.forms.Form.initial ize(Form.java:201)
at org.jboss.tools.common.model.ui.forms.FormContaine r.initialize(FormContainer.java:70)
at org.jboss.tools.common.editor.TreeFormPage.selecti onChanged(TreeFormPage.java:218)
at org.jboss.tools.common.editor.SelectionNotifier.fi reSelectionChanged(SelectionNotifier.java:63)
at org.jboss.tools.common.editor.SelectionNotifier.se lectionChanged(SelectionNotifier.java:39)
at org.eclipse.jface.viewers.Viewer$2.run(Viewer.java :162)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner .java:42)
at org.eclipse.core.runtime.Platform.run(Platform.jav a:888)
at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil. java:48)
at org.eclipse.jface.util.SafeRunnable.run(SafeRunnab le.java:175)
at org.eclipse.jface.viewers.Viewer.fireSelectionChan ged(Viewer.java:160)
at org.eclipse.jface.viewers.StructuredViewer.updateS election(StructuredViewer.java:2132)
at org.eclipse.jface.viewers.StructuredViewer.setSele ction(StructuredViewer.java:1669)
at org.eclipse.jface.viewers.TreeViewer.setSelection( TreeViewer.java:1124)
at org.eclipse.jface.viewers.Viewer.setSelection(View er.java:392)
at org.jboss.tools.common.editor.XModelObjectTreeView Component$1.run(XModelObjectTreeViewComponent.java :106)
at org.eclipse.swt.widgets.RunnableLock.run(RunnableL ock.java:35)
at org.eclipse.swt.widgets.Synchronizer.runAsyncMessa ges(Synchronizer.java:134)
at org.eclipse.swt.widgets.Display.runAsyncMessages(D isplay.java:3885)
at org.eclipse.swt.widgets.Display.readAndDispatch(Di splay.java:3506)
at org.eclipse.ui.internal.Workbench.runEventLoop(Wor kbench.java:2405)
at org.eclipse.ui.internal.Workbench.runUI(Workbench. java:2369)
at org.eclipse.ui.internal.Workbench.access$4(Workben ch.java:2221)
at org.eclipse.ui.internal.Workbench$5.run(Workbench. java:500)
at org.eclipse.core.databinding.observable.Realm.runW ithDefault(Realm.java:332)
at org.eclipse.ui.internal.Workbench.createAndRunWork bench(Workbench.java:493)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(Pl atformUI.java:149)
at org.eclipse.ui.internal.ide.application.IDEApplica tion.start(IDEApplication.java:113)
at org.eclipse.equinox.internal.app.EclipseAppHandle. run(EclipseAppHandle.java:194)
at org.eclipse.core.runtime.internal.adaptor.EclipseA ppLauncher.runApplication(EclipseAppLauncher.java: 110)
at org.eclipse.core.runtime.internal.adaptor.EclipseA ppLauncher.start(EclipseAppLauncher.java:79)
at org.eclipse.core.runtime.adaptor.EclipseStarter.ru n(EclipseStarter.java:368)
at org.eclipse.core.runtime.adaptor.EclipseStarter.ru n(EclipseStarter.java:179)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Nativ e Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Native MethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(De legatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.equinox.launcher.Main.invokeFramework( Main.java:559)
at org.eclipse.equinox.launcher.Main.basicRun(Main.ja va:514)
at org.eclipse.equinox.launcher.Main.run(Main.java:13 11)
at org.eclipse.equinox.launcher.Main.main(Main.java:1 287)

And because of that, I cannot build and execute the application.
I am trying to solve it last one week but didn't get any solution.
Please, help me to solve

Regards
Gautam