Hi all! I have this strange problem with the UltraTabControl in a production environment.

- The famous red cross... I know this is a thread related issue, but I don't find the cause.
   We have a central menu application from which all programs are loaded in a new threads:

   Thread thread2 = new Thread(() => { Form2 f2 = new Form2(); Application.Run(f2); });
   thread2.SetApartmentState(AppartmentState.STA);
   thread2.Start();

   Once the sub-program is launched, there is no interaction between the menu and this program.

- This error occurs approximately once in the week and only by ONE user.

- At the moment the error occurs, the user is not working in the application. So it crashes when the program is in an inactive/idle state.

- We had a simular problem (red cross) earlier with the UltraStatusBar, but in that case all the users were affected. Removing the date- and time-panel from the UltraWinStatusBar resolved the problem.

Can someone give me a hint where I have to search to solve this issue? @Mike Saltzman, you perhaps? (Fan of your posts!) 

This is the exact error and stacktrace.

Error: Index was outside the bounds of the array.

Stack:
at System.Collections.Generic.HashSet`1.SetCapacity(Int32 newSize, Boolean forceNewHashCodes)
at System.Collections.Generic.HashSet`1.AddIfNotPresent(T value)
at Infragistics.Win.Notifications.NotificationUIElement.AddNotificationUIElementIfPossible(UIElement parent, INotificationBadgeProvider notificationProvider)
at Infragistics.Win.UIElement.VerifyChildElements(ControlUIElementBase controlElement, Boolean recursive)
at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
at Infragistics.Win.UIElement.DrawChildElements(UIElementDrawParams& drawParams)
at Infragistics.Win.UIElement.DrawElement(UIElementDrawParams& defaultDrawParams)
at Infragistics.Win.UIElement.DrawHelper(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Boolean clipText, Boolean forceDrawAsFocused, Boolean preventAlphaBlendGraphics, Nullable`1 zoomFactor)
at Infragistics.Win.ControlUIElementBase.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode, Size elementSize, Boolean preventAlphaBlendGraphics)
at Infragistics.Win.ControlUIElementBase.Draw(Graphics graphics, Rectangle invalidRectangle, Boolean doubleBuffer, AlphaBlendMode alphaBlendMode)
at Infragistics.Win.UltraControlBase.OnPaint(PaintEventArgs pe)
at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer)
at System.Windows.Forms.Control.WmPaint(Message& m)
at System.Windows.Forms.Control.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)