When I close Eclipse a message indicates some problem on Workbench configuration. Where is the problem ?
See below log file:
!SESSION 2007-02-27 01:54:25.312 -----------------------------------------------
eclipse.buildId=M20060629-1905
java.version=1.4.2_03
java.vendor=Sun Microsystems Inc.
BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=es_ES
Command-line arguments: -data C:\aplic\eclipse3.2 -os win32 -ws win32 -arch x86

This is a continuation of log file C:\aplic\eclipse3.2\.metadata\.bak_0.log
Created Time: 2007-02-27 01:55:14.343

!ENTRY org.eclipse.ui.workbench 4 2 2007-02-27 01:55:14.343
!MESSAGE Problems occurred when invoking code from plug-in: "org.eclipse.ui.workbench".
!STACK 0
org.eclipse.jface.text.Assert$AssertionFailedException: null argument;
at org.eclipse.jface.text.Assert.isNotNull(Assert.java:157)
at org.eclipse.jface.text.Assert.isNotNull(Assert.java:133)
at org.eclipse.jface.text.contentassist.ContentAssistant.setRepeatedInvocationTrigger(ContentAssistant.java:2125)
at org.eclipse.jdt.internal.ui.text.java.ContentAssistProcessor$2.assistSessionEnded(ContentAssistProcessor.java:192)
at org.eclipse.jface.text.contentassist.ContentAssistant.fireSessionEndEvent(ContentAssistant.java:2008)
at org.eclipse.jface.text.contentassist.CompletionProposalPopup.hide(CompletionProposalPopup.java:868)
at org.eclipse.jface.text.contentassist.ContentAssistant.hide(ContentAssistant.java:1835)
at org.eclipse.jface.text.contentassist.ContentAssistant.uninstall(ContentAssistant.java:1199)
at org.eclipse.jface.text.source.SourceViewer.unconfigure(SourceViewer.java:587)
at org.eclipse.jdt.internal.ui.javaeditor.JavaSourceViewer.unconfigure(JavaSourceViewer.java:349)
at org.eclipse.jface.text.source.SourceViewer.handleDispose(SourceViewer.java:633)
at org.eclipse.jface.text.source.projection.ProjectionViewer.handleDispose(ProjectionViewer.java:1351)
at org.eclipse.jdt.internal.ui.javaeditor.JavaSourceViewer.handleDispose(JavaSourceViewer.java:459)
at org.eclipse.jface.text.TextViewer$1.widgetDisposed(TextViewer.java:1483)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:101)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:928)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:952)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:937)
at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:709)
at org.eclipse.swt.custom.StyledText.handleDispose(StyledText.java:4920)
at org.eclipse.swt.custom.StyledText$7.handleEvent(StyledText.java:4787)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:928)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:952)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:933)
at org.eclipse.swt.widgets.Widget.release(Widget.java:743)
at org.eclipse.swt.widgets.Composite.releaseChildren(Composite.java:636)
at org.eclipse.swt.widgets.Canvas.releaseChildren(Canvas.java:117)
at org.eclipse.swt.widgets.Widget.release(Widget.java:746)
at org.eclipse.swt.widgets.Composite.releaseChildren(Composite.java:636)
at org.eclipse.swt.widgets.Widget.release(Widget.java:746)
at org.eclipse.swt.widgets.Composite.releaseChildren(Composite.java:636)
at org.eclipse.swt.widgets.Widget.release(Widget.java:746)
at org.eclipse.swt.widgets.Composite.releaseChildren(Composite.java:636)
at org.eclipse.swt.widgets.Widget.release(Widget.java:746)
at org.eclipse.swt.widgets.Composite.releaseChildren(Composite.java:636)
at org.eclipse.swt.widgets.Widget.release(Widget.java:746)
at org.eclipse.swt.widgets.Widget.dispose(Widget.java:415)
at org.eclipse.ui.internal.PartPane.dispose(PartPane.java:167)
at org.eclipse.ui.internal.WorkbenchPartReference.dispose(WorkbenchPartReference.java:639)
at org.eclipse.ui.internal.WorkbenchPage.disposePart(WorkbenchPage.java:1541)
at org.eclipse.ui.internal.WorkbenchPage.handleDeferredEvents(WorkbenchPage.java:1311)
at org.eclipse.ui.internal.WorkbenchPage.deferUpdates(WorkbenchPage.java:1295)
at org.eclipse.ui.internal.WorkbenchPage.closeEditors(WorkbenchPage.java:1269)
at org.eclipse.ui.internal.WorkbenchPage.closeAllEditors(WorkbenchPage.java:1088)
at org.eclipse.ui.internal.WorkbenchPage.dispose(WorkbenchPage.java:1590)
at org.eclipse.ui.internal.WorkbenchWindow.closeAllPages(WorkbenchWindow.java:748)
at org.eclipse.ui.internal.WorkbenchWindow.hardClose(WorkbenchWindow.java:1486)
at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:622)
at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:598)
at org.eclipse.ui.internal.WorkbenchWindow$2.run(WorkbenchWindow.java:713)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:711)
at org.eclipse.jface.window.WindowManager.close(WindowManager.java:109)
at org.eclipse.ui.internal.Workbench$12.run(Workbench.java:712)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:37)
at org.eclipse.ui.internal.Workbench.busyClose(Workbench.java:709)
at org.eclipse.ui.internal.Workbench.access$8(Workbench.java:639)
at org.eclipse.ui.internal.Workbench$14.run(Workbench.java:839)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
at org.eclipse.ui.internal.Workbench.close(Workbench.java:837)
at org.eclipse.ui.internal.Workbench.close(Workbench.java:812)
at org.eclipse.ui.internal.WorkbenchWindow.busyClose(WorkbenchWindow.java:619)
at org.eclipse.ui.internal.WorkbenchWindow.access$0(WorkbenchWindow.java:598)
at org.eclipse.ui.internal.WorkbenchWindow$2.run(WorkbenchWindow.java:713)
at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67)
at org.eclipse.ui.internal.WorkbenchWindow.close(WorkbenchWindow.java:711)
at org.eclipse.jface.window.Window.handleShellCloseEvent(Window.java:736)
at org.eclipse.jface.window.Window$3.shellClosed(Window.java:682)
at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:159)
at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:928)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:952)
at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:937)
at org.eclipse.swt.widgets.Decorations.closeWidget(Decorations.java:257)
at org.eclipse.swt.widgets.Decorations.WM_CLOSE(Decorations.java:1606)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3248)
at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1539)
at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:1634)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4025)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:1918)
at org.eclipse.swt.widgets.Shell.callWindowProc(Shell.java:443)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3334)
at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1539)
at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:1634)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4025)
at org.eclipse.swt.internal.win32.OS.DefWindowProcW(Native Method)
at org.eclipse.swt.internal.win32.OS.DefWindowProc(OS.java:1918)
at org.eclipse.swt.widgets.Shell.callWindowProc(Shell.java:443)
at org.eclipse.swt.widgets.Control.windowProc(Control.java:3334)
at org.eclipse.swt.widgets.Decorations.windowProc(Decorations.java:1539)
at org.eclipse.swt.widgets.Shell.windowProc(Shell.java:1634)
at org.eclipse.swt.widgets.Display.windowProc(Display.java:4025)
at org.eclipse.swt.internal.win32.OS.DispatchMessageW(Native Method)
at org.eclipse.swt.internal.win32.OS.DispatchMessage(OS.java:1923)
at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:2966)
at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:1914)
at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:1878)
at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:419)
at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
at org.eclipse.ui.internal.ide.IDEApplication.run(IDEApplication.java:95)
at org.eclipse.core.internal.runtime.PlatformActivator$1.run(PlatformActivator.java:78)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:92)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:68)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:400)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:177)
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.core.launcher.Main.invokeFramework(Main.java:336)
at org.eclipse.core.launcher.Main.basicRun(Main.java:280)
at org.eclipse.core.launcher.Main.run(Main.java:977)
at org.eclipse.core.launcher.Main.main(Main.java:952)