title: Silverlight ChildWindow: HRESULT E_FAIL on ChildWindow.Show()
body: <p>I have some problems with ChildWindow control, I have created an error window control that is shown after unhandled exception is caught in app.xaml.cs. The problem is when I try to show the error window, sometimes it works fine, but sometimes I get this nasty exception: </p>
  
  <p>Message: 
  Error HRESULT E_FAIL has been returned from a call to a COM component. </p>
  
  <p>Stack Trace: 
  at MS.Internal.XcpImports.CheckHResult(UInt32 hr) at MS.Internal.XcpImports.SetValue(INativeCoreTypeWrapper obj, DependencyProperty property, Boolean b) at System.Windows.DependencyObject.SetValue(DependencyProperty property, Boolean b) at System.Windows.Controls.Primitives.Popup.set_IsOpen(Boolean value) at System.Windows.Controls.ChildWindow.Show() at FrontEnd.SL.Util.GuiLogger.ShowErrorWindow(ErrorDetails details, ErrorSeverity severity) </p>
  
  <p><br>
  the trace you see is inside the Show() method of the ChildWindow. 
  <br>
  In another words, my code is:<br>
  ErrorWindow errorWin= new ErrorWindow();<br>
  errorWin.Show();
  <br>
  where ErrorWindow:ChildWindow
  <br><br>
  any help is greatly appreciated..</p>