I can't find the window builder in Eclipse indigo -

i installed windowbuilder given guidelines. installed. when i'm going window ==> show view ==> pallet i'm getting error:

could not create view: plug-in org.eclipse.wb.core unable load class org.eclipse.wb.internal.core.views.paletteview. <br/> in details <br/> org.eclipse.core.runtime.internal.adaptor.eclipselazystarter$terminatingclassnotfoundexception: error occurred while automatically activating bundle org.eclipse.wb.core (763).     @ org.eclipse.core.runtime.internal.adaptor.eclipselazystarter.postfindlocalclass(eclipselazystarter.java:122)     @ org.eclipse.osgi.baseadaptor.loader.classpathmanager.findlocalclass(classpathmanager.java:463)     @ org.eclipse.osgi.internal.baseadaptor.defaultclassloader.findlocalclass(defaultclassloader.java:216)     @ org.eclipse.osgi.internal.loader.bundleloader.findlocalclass(bundleloader.java:400)     @ org.eclipse.osgi.internal.loader.bundleloader.findclassinternal(bundleloader.java:476)     @ org.eclipse.osgi.internal.loader.bundleloader.findclass(bundleloader.java:429)     @ org.eclipse.osgi.internal.loader.bundleloader.findclass(bundleloader.java:417)     @ org.eclipse.osgi.internal.baseadaptor.defaultclassloader.loadclass(defaultclassloader.java:107)     @ java.lang.classloader.loadclass(unknown source)     @ org.eclipse.osgi.internal.loader.bundleloader.loadclass(bundleloader.java:345)     @ org.eclipse.osgi.framework.internal.core.bundlehost.loadclass(bundlehost.java:229)     @ org.eclipse.osgi.framework.internal.core.abstractbundle.loadclass(abstractbundle.java:1207)     @ org.eclipse.core.internal.registry.osgi.registrystrategyosgi.createexecutableextension(registrystrategyosgi.java:174)     @ org.eclipse.core.internal.registry.extensionregistry.createexecutableextension(extensionregistry.java:905)     @ org.eclipse.core.internal.registry.configurationelement.createexecutableextension(configurationelement.java:243)     @ org.eclipse.core.internal.registry.configurationelementhandle.createexecutableextension(configurationelementhandle.java:55)     @ org.eclipse.ui.internal.workbenchplugin$1.run(workbenchplugin.java:268)     @ org.eclipse.swt.custom.busyindicator.showwhile(busyindicator.java:70)     @ org.eclipse.ui.internal.workbenchplugin.createextension(workbenchplugin.java:264)     @ org.eclipse.ui.internal.registry.viewdescriptor.createview(viewdescriptor.java:63)     @ org.eclipse.ui.internal.viewreference.createparthelper(viewreference.java:327)     @ org.eclipse.ui.internal.viewreference.createpart(viewreference.java:229)     @ org.eclipse.ui.internal.workbenchpartreference.getpart(workbenchpartreference.java:595)     @ org.eclipse.ui.internal.perspective.showview(perspective.java:2245)     @ org.eclipse.ui.internal.workbenchpage.busyshowview(workbenchpage.java:1145)     @ org.eclipse.ui.internal.workbenchpage$20.run(workbenchpage.java:3921)     @ org.eclipse.swt.custom.busyindicator.showwhile(busyindicator.java:70)     @ org.eclipse.ui.internal.workbenchpage.showview(workbenchpage.java:3918)     @ org.eclipse.ui.handlers.showviewhandler.openview(showviewhandler.java:162)     @ org.eclipse.ui.handlers.showviewhandler.openother(showviewhandler.java:105)     @ org.eclipse.ui.handlers.showviewhandler.execute(showviewhandler.java:73)     @ org.eclipse.ui.internal.handlers.handlerproxy.execute(handlerproxy.java:293)     @ org.eclipse.core.commands.command.executewithchecks(command.java:476)     @ org.eclipse.core.commands.parameterizedcommand.executewithchecks(parameterizedcommand.java:508)     @ org.eclipse.ui.internal.handlers.handlerservice.executecommand(handlerservice.java:169)     @ org.eclipse.ui.internal.handlers.slavehandlerservice.executecommand(slavehandlerservice.java:241)     @ org.eclipse.ui.internal.showviewmenu$3.run(showviewmenu.java:187)     @ org.eclipse.jface.action.action.runwithevent(action.java:498)     @ org.eclipse.jface.action.actioncontributionitem.handlewidgetselection(actioncontributionitem.java:584)     @ org.eclipse.jface.action.actioncontributionitem.access$2(actioncontributionitem.java:501)     @ org.eclipse.jface.action.actioncontributionitem$5.handleevent(actioncontributionitem.java:411)     @ org.eclipse.swt.widgets.eventtable.sendevent(eventtable.java:84)     @ org.eclipse.swt.widgets.widget.sendevent(widget.java:1053)     @ org.eclipse.swt.widgets.display.rundeferredevents(display.java:4165)     @ org.eclipse.swt.widgets.display.readanddispatch(display.java:3754)     @ org.eclipse.ui.internal.workbench.runeventloop(workbench.java:2701)     @ org.eclipse.ui.internal.workbench.runui(workbench.java:2665)     @ org.eclipse.ui.internal.workbench.access$4(workbench.java:2499)     @ org.eclipse.ui.internal.workbench$7.run(workbench.java:679)     @ org.eclipse.core.databinding.observable.realm.runwithdefault(realm.java:332)     @ org.eclipse.ui.internal.workbench.createandrunworkbench(workbench.java:668)     @ org.eclipse.ui.platformui.createandrunworkbench(platformui.java:149)     @ org.eclipse.ui.internal.ide.application.ideapplication.start(ideapplication.java:123)     @ org.eclipse.equinox.internal.app.eclipseapphandle.run(eclipseapphandle.java:196)     @ org.eclipse.core.runtime.internal.adaptor.eclipseapplauncher.runapplication(eclipseapplauncher.java:110)     @ org.eclipse.core.runtime.internal.adaptor.eclipseapplauncher.start(eclipseapplauncher.java:79)     @ org.eclipse.core.runtime.adaptor.eclipsestarter.run(eclipsestarter.java:344)     @ org.eclipse.core.runtime.adaptor.eclipsestarter.run(eclipsestarter.java:179)     @ sun.reflect.nativemethodaccessorimpl.invoke0(native method)     @ sun.reflect.nativemethodaccessorimpl.invoke(unknown source)     @ sun.reflect.delegatingmethodaccessorimpl.invoke(unknown source)     @ java.lang.reflect.method.invoke(unknown source)     @ org.eclipse.equinox.launcher.main.invokeframework(main.java:622)     @ org.eclipse.equinox.launcher.main.basicrun(main.java:577)     @ org.eclipse.equinox.launcher.main.run(main.java:1410) caused by: org.osgi.framework.bundleexception: activator org.eclipse.wb.internal.core.designerplugin bundle org.eclipse.wb.core invalid     @ org.eclipse.osgi.framework.internal.core.abstractbundle.loadbundleactivator(abstractbundle.java:171)     @ org.eclipse.osgi.framework.internal.core.bundlecontextimpl.start(bundlecontextimpl.java:679)     @ org.eclipse.osgi.framework.internal.core.bundlehost.startworker(bundlehost.java:381)     @ org.eclipse.osgi.framework.internal.core.abstractbundle.start(abstractbundle.java:299)     @ org.eclipse.osgi.framework.util.secureaction.start(secureaction.java:440)     @ org.eclipse.osgi.internal.loader.bundleloader.setlazytrigger(bundleloader.java:268)     @ org.eclipse.core.runtime.internal.adaptor.eclipselazystarter.postfindlocalclass(eclipselazystarter.java:107)     ... 64 more caused by: java.lang.noclassdeffounderror: com/google/common/collect/maps     @ org.eclipse.wb.internal.core.bundleresourceprovider.<clinit>(bundleresourceprovider.java:48)     @ org.eclipse.wb.internal.core.designerplugin.<clinit>(designerplugin.java:398)     @ sun.reflect.nativeconstructoraccessorimpl.newinstance0(native method)     @ sun.reflect.nativeconstructoraccessorimpl.newinstance(unknown source)     @ sun.reflect.delegatingconstructoraccessorimpl.newinstance(unknown source)     @ java.lang.reflect.constructor.newinstance(unknown source)     @ java.lang.class.newinstance(unknown source)     @ org.eclipse.osgi.framework.internal.core.abstractbundle.loadbundleactivator(abstractbundle.java:166)     ... 70 more caused by: java.lang.classnotfoundexception: com.google.common.collect.maps     @ org.eclipse.osgi.internal.loader.bundleloader.findclassinternal(bundleloader.java:513)     @ org.eclipse.osgi.internal.loader.bundleloader.findclass(bundleloader.java:429)     @ org.eclipse.osgi.internal.loader.bundleloader.findclass(bundleloader.java:417)     @ org.eclipse.osgi.internal.baseadaptor.defaultclassloader.loadclass(defaultclassloader.java:107)     @ java.lang.classloader.loadclass(unknown source)     ... 78 more