Null pane with custom RemovePane method

[boon]

I'm getting a null reference exception when closing one of the pane and could not figure out why it is null in the RemovePane(RadPane pane) method.

We have override to that method,

protected override void RemovePane(RadPane pane)
        {
            if(pane.Header.ToString().ToLower()=="digital" || pane.Header.ToString().ToLower() == "analog")
                SaveDebugPaneLayout(pane);
            pane.DataContext = null;
            pane.Content = null;
            pane.ClearValue(RadDocking.SerializationTagProperty);
            pane.RemoveFromParent();
        }

And also the CreatePaneForItem method,

protected override RadPane CreatePaneForItem(object item)
        {
            var viewModel = item as DebugPaneViewModel;
            if (viewModel != null)
            {
                var pane = viewModel.IsDocument ? new RadDocumentPane() : new RadPane();

                pane.DataContext = item;
    
                if (viewModel.ContentType != null)
                {
                    if (viewModel.GetType().ToString().EndsWith("EditorViewModel")) 
                    {
                        if (pane.Content == null)
                        {
                            dynamic obj = Activator.CreateInstance(viewModel.ContentType);
                            pane.Content = obj;
                            obj.DataContext = viewModel;
                        }
                    }
                    else
                    {
                        pane.Content = Activator.CreateInstance(viewModel.ContentType);
                    }
                }

                RadDocking.SetSerializationTag(pane, viewModel.ID);
                return pane;
            }

            return base.CreatePaneForItem(item);
        }

How can I know which pane is null when it is executing the RemovePane(). I tried looking at when panes are being added but did not see anything suspicious.

[Stenly]

Is there a possibility to share a sample project that reproduces the null reference exception or a bit more information so that I can reproduce it on my side? Also, what is the version of the assemblies that are used on your side?