Developer Activity & Statistics Monitor Eclipse Project

I have installed xtext/xtend 2.4.3.v201309030823

Error
Wed Nov 13 14:11:22 AST 2013
Errors running builder 'Xtext Project Builder' on project '.snipmatch'.

java.lang.NoClassDefFoundError: org/eclipse/xtext/xbase/lib/ArrayLiterals
at org.eclipse.xtext.xbase.scoping.batch.ImplicitlyImportedTypes.getStaticImportClasses(ImplicitlyImportedTypes.java:89)
at org.eclipse.xtext.xbase.scoping.batch.ImplicitlyImportedTypes.getStaticImportClasses(ImplicitlyImportedTypes.java:62)
at org.eclipse.xtext.xbase.scoping.batch.XbaseBatchScopeProvider.newSession(XbaseBatchScopeProvider.java:83)
at org.eclipse.xtext.xbase.typesystem.internal.DefaultReentrantTypeResolver.resolve(DefaultReentrantTypeResolver.java:209)
at org.eclipse.xtext.xbase.typesystem.internal.DefaultReentrantTypeResolver.reentrantResolve(DefaultReentrantTypeResolver.java:197)
at org.eclipse.xtext.xbase.typesystem.internal.DefaultBatchTypeResolver$1.reentrantResolve(DefaultBatchTypeResolver.java:122)
at org.eclipse.xtext.xbase.typesystem.internal.CachingBatchTypeResolver$LazyResolvedTypes.delegate(CachingBatchTypeResolver.java:114)
at org.eclipse.xtext.xbase.typesystem.internal.CachingBatchTypeResolver$2.process(CachingBatchTypeResolver.java:61)
at org.eclipse.xtext.xbase.typesystem.internal.CachingBatchTypeResolver$2.process(CachingBatchTypeResolver.java:1)
at org.eclipse.xtext.util.concurrent.IUnitOfWork$Void.exec(IUnitOfWork.java:36)
at org.eclipse.xtext.util.OnChangeEvictingCache.execWithoutCacheClear(OnChangeEvictingCache.java:127)
at org.eclipse.xtext.xbase.typesystem.internal.CachingBatchTypeResolver.resolveTypes(CachingBatchTypeResolver.java:58)
at org.eclipse.xtext.xbase.resource.BatchLinkingService.resolveBatched(BatchLinkingService.java:45)
at org.eclipse.xtext.xbase.resource.BatchLinkableResource.resolveLazyCrossReferences(BatchLinkableResource.java:142)
at org.eclipse.xtext.EcoreUtil2.resolveLazyCrossReferences(EcoreUtil2.java:511)
at org.eclipse.xtext.builder.clustering.ClusteringBuilderState.doUpdate(ClusteringBuilderState.java:214)
at org.eclipse.xtext.builder.builderState.AbstractBuilderState.update(AbstractBuilderState.java:111)
at org.eclipse.xtext.builder.impl.XtextBuilder.doBuild(XtextBuilder.java:184)
at org.eclipse.xtext.builder.impl.XtextBuilder.incrementalBuild(XtextBuilder.java:162)
at org.eclipse.xtext.builder.impl.XtextBuilder.build(XtextBuilder.java:95)
at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:733)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:206)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:246)
at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:299)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)
at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:302)
at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:358)
at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:381)
at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:143)
at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:241)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:53)