java.lang.NullPointerException: This exception has no message.

java.lang.NullPointerException	at java.util.concurrent.ConcurrentHashMap.containsKey(ConcurrentHashMap.java:782)	at org.springframework.ide.eclipse.beans.core.internal.model.namespaces.ProjectClasspathNamespaceDefinitionResolver.init(ProjectClasspathNamespaceDefinitionResolver.java:146)	at org.springframework.ide.eclipse.beans.core.internal.model.namespaces.ProjectClasspathNamespaceDefinitionResolver.<init>(ProjectClasspathNamespaceDefinitionResolver.java:78)	at org.springframework.ide.eclipse.beans.core.internal.model.namespaces.ProjectClasspathNamespaceDefinitionResolverCache$ResolvlerCacheEntry.<init>(ProjectClasspathNamespaceDefinitionResolverCache.java:112)	at org.springframework.ide.eclipse.beans.core.internal.model.namespaces.ProjectClasspathNamespaceDefinitionResolverCache.addResolverToCache(ProjectClasspathNamespaceDefinitionResolverCache.java:59)	at org.springframework.ide.eclipse.beans.core.internal.model.namespaces.ProjectClasspathNamespaceDefinitionResolverCache.getResolver(ProjectClasspathNamespaceDefinitionResolverCache.java:94)	at org.springframework.ide.eclipse.beans.core.BeansCorePlugin.getNamespaceDefinitionResolver(BeansCorePlugin.java:195)	at org.springframework.ide.eclipse.beans.ui.namespaces.DefaultNamespaceLabelProvider.getImage(DefaultNamespaceLabelProvider.java:63)	at org.springframework.ide.eclipse.beans.ui.namespaces.TxNamespaceLabelProvider.getImage(TxNamespaceLabelProvider.java:42)	at org.springframework.ide.eclipse.beans.ui.model.BeansModelLabelProvider.getImage(BeansModelLabelProvider.java:66)	at org.springframework.ide.eclipse.beans.ui.navigator.BeansNavigatorLabelProvider.getImage(BeansNavigatorLabelProvider.java:146)	at org.springframework.ide.eclipse.ui.viewers.DecoratingWorkbenchTreePathLabelProvider.getImage(DecoratingWorkbenchTreePathLabelProvider.java:52)	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.findImage(NavigatorContentServiceLabelProvider.java:197)	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.getColumnImage(NavigatorContentServiceLabelProvider.java:105)	at org.eclipse.ui.internal.navigator.NavigatorContentServiceLabelProvider.getImage(NavigatorContentServiceLabelProvider.java:98)	at org.eclipse.ui.internal.navigator.NavigatorDecoratingLabelProvider$StyledLabelProviderAdapter.getImage(NavigatorDecoratingLabelProvider.java:60)	at org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.getImage(DelegatingStyledCellLabelProvider.java:184)	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider.getImage(DecoratingStyledCellLabelProvider.java:167)	at org.eclipse.jface.viewers.DelegatingStyledCellLabelProvider.update(DelegatingStyledCellLabelProvider.java:118)	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider.update(DecoratingStyledCellLabelProvider.java:134)	at org.eclipse.jface.viewers.ViewerColumn.refresh(ViewerColumn.java:152)	at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:934)	at org.eclipse.jface.viewers.AbstractTreeViewer$UpdateItemSafeRunnable.run(AbstractTreeViewer.java:102)	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)	at org.eclipse.jface.viewers.AbstractTreeViewer.doUpdateItem(AbstractTreeViewer.java:1014)	at org.eclipse.jface.viewers.StructuredViewer$UpdateItemSafeRunnable.run(StructuredViewer.java:481)	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)	at org.eclipse.jface.viewers.StructuredViewer.updateItem(StructuredViewer.java:2141)	at org.eclipse.jface.viewers.StructuredViewer.internalUpdate(StructuredViewer.java:2124)	at org.eclipse.jface.viewers.StructuredViewer.update(StructuredViewer.java:2063)	at org.eclipse.jface.viewers.ColumnViewer.update(ColumnViewer.java:554)	at org.eclipse.ui.navigator.CommonViewer.update(CommonViewer.java:535)	at org.eclipse.jface.viewers.StructuredViewer.update(StructuredViewer.java:2007)	at org.eclipse.jface.viewers.StructuredViewer.handleLabelProviderChanged(StructuredViewer.java:1170)	at org.eclipse.ui.navigator.CommonViewer.handleLabelProviderChanged(CommonViewer.java:235)	at org.eclipse.jface.viewers.ContentViewer$1.labelProviderChanged(ContentViewer.java:97)	at org.eclipse.jface.viewers.BaseLabelProvider$1.run(BaseLabelProvider.java:74)	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)	at org.eclipse.ui.internal.JFaceUtil$1.run(JFaceUtil.java:49)	at org.eclipse.jface.util.SafeRunnable.run(SafeRunnable.java:175)	at org.eclipse.jface.viewers.BaseLabelProvider.fireLabelProviderChanged(BaseLabelProvider.java:72)	at org.eclipse.jface.viewers.DecoratingStyledCellLabelProvider$1.labelProviderChanged(DecoratingStyledCellLabelProvider.java:77)	at org.eclipse.ui.internal.decorators.DecoratorManager$1.run(DecoratorManager.java:430)	at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42)	at org.eclipse.ui.internal.decorators.DecoratorManager.fireListener(DecoratorManager.java:428)	at org.eclipse.ui.internal.decorators.DecorationScheduler$3.runInUIThread(DecorationScheduler.java:530)	at org.eclipse.ui.progress.UIJob$1.run(UIJob.java:95)	at org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:35)	at org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:134)	at org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:4041)	at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3660)	at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2629)	at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2593)	at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2427)	at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:670)	at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)	at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:663)	at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)	at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:115)	at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)	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:369)	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:619)	at org.eclipse.equinox.launcher.Main.basicRun(Main.java:574)	at org.eclipse.equinox.launcher.Main.run(Main.java:1407)