NullReferenceException in Krypton Toolkit.

[han]

We are using Krypton Toolkit for some dialogs and the like in our program. Although we cannot reproduce it, some of our customers get crashes with the following stack trace:

<exception type="System.ArgumentNullException">
<message>Value cannot be null.
Parameter name: region</message>
<stacktrace>
at System.Drawing.Graphics.SetClip(Region region, CombineMode combineMode)
at ComponentFactory.Krypton.Toolkit.ViewDrawSplitCanvas.RenderAfter(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewComposite.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewComposite.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewDrawButton.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewComposite.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewComposite.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewDecorator.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewComposite.Render(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewManager.Paint(RenderContext context)
at ComponentFactory.Krypton.Toolkit.ViewManager.Paint(IRenderer renderer, PaintEventArgs e)
at ComponentFactory.Krypton.Toolkit.KryptonForm.a(Graphics A_0, Rectangle A_1)
at ComponentFactory.Krypton.Toolkit.KryptonForm.WindowChromePaint(Graphics g, Rectangle bounds)
at ComponentFactory.Krypton.Toolkit.VisualForm.OnNonClientPaint(IntPtr hWnd)
at ComponentFactory.Krypton.Toolkit.VisualForm.OnWM_NCPAINT(Message&amp; m)
at ComponentFactory.Krypton.Toolkit.VisualForm.WndProc(Message&amp; m)
at P1.C1.MainForm.WndProc(Message&amp; m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)</stacktrace>
</exception>

Since I can't reproduce it and the last line in the stacktrace is in native code, I don't quite know how to go about this. I'd be very grateful of ideas about what could cause this.

Kind regards
Hannes