Steps to reproduce:
1. Add a chart to a form.
2. Add any cartesian series
3. Set the LabelFitMode of the horizontal axis to Rotate.

You will see that labels have incorrect layout.

To reproduce:
- Add at least two series and zoom the chart so the point from one of the series are visible only
- Move the TrackBall
- The Track ball is not shown for some of the points. 

Currently RadChartView does not support null values.

To reproduce:
public Form1()
{
    InitializeComponent();

    ScatterSeries series = new ScatterSeries();
    series.DataPoints.Add(new ScatterDataPoint(5, 5));
    series.DataPoints.Add(new ScatterDataPoint(4, 2));
    series.DataPoints.Add(new ScatterDataPoint(-1, 3));
    series.DataPoints.Add(new ScatterDataPoint(8, 4));

    radChartView1.Series.Add(series);

    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.Minimum = -10;
    horizontalAxis.Maximum = 10;
}
private void radButton1_Click(object sender, EventArgs e)
{
    LinearAxis horizontalAxis = radChartView1.Axes.Get<LinearAxis>(0);
    horizontalAxis.DesiredTickCount = 20;
}

Steps to reproduce.

1. Add a chart view to a form.
2. Create a series and add several data points. For categories use double values in the range 10 - 20
3. Create a second series and this time for categories use double values in the same range without duplication.
4. Assign one linear and one categorical axis to the series and add them to the char view.
5. Run the project and you will see that the categories from the second series are next to those from the first series, while they should be combined according their values.

I'm using version 2012.3.1310.40
I use ChartView to create a pie chart with the following data
Assets          2248550.22
Income             19748.67
Equity           2228253.95
Liability                 547.60

So, when the chart displays, the Percentage is set as follows:
Assets       50%
Income        0%
Equity         50%
Liability        0%

I notice when the percentage is 0% for any data, the pie chart shows "0%" near the chart title (please see attachment).  Or if the calculated data returns 0, it doesn't show any percentage on the chart, but it will shows "NaN" near the title as well. (please see attachment).

Note: similar to the axis, the series should also have ClipLabels property which will control whether the labels will be clipped or not.

How to reproduce: zoom and pan along the chart
public Form1()
{
    InitializeComponent();

    this.radChartView1.CreateRenderer += radChartView1_CreateRenderer;
    this.radChartView1.ShowPanZoom = true;

    BarSeries barSeries = new BarSeries();
    Random rand = new Random();
    for (int i = 1; i < 10; i++)
    {
        barSeries.DataPoints.Add(new CategoricalDataPoint(rand.Next(100), i));
    }

    barSeries.ShowLabels = true;
    this.radChartView1.Series.Add(barSeries);
}

Workaround:
 public partial class Form1 : Form
 {
     public Form1()
     {
         InitializeComponent();

         this.radChartView1.CreateRenderer += radChartView1_CreateRenderer;
         this.radChartView1.ShowPanZoom = true;

         BarSeries barSeries = new BarSeries();
         Random rand = new Random();
         for (int i = 1; i < 10; i++)
         {
             barSeries.DataPoints.Add(new CategoricalDataPoint(rand.Next(100), i));
         }

         barSeries.ShowLabels = true;
         this.radChartView1.Series.Add(barSeries);
     }

     private void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
     {
         e.Renderer = new CustomCartesianRenderer(e.Area as CartesianArea);
     }
 }

 public class CustomCartesianRenderer : CartesianRenderer
 {
     public CustomCartesianRenderer(CartesianArea area)
         : base(area)
     { }
     protected override void Initialize()
     {
         base.Initialize();

         for (int i = 0; i < this.DrawParts.Count; i++)
         {
             BarLabelElementDrawPart labelPart = this.DrawParts[i] as BarLabelElementDrawPart;
             if (labelPart != null)
             {
                 this.DrawParts[i] = new CustomLabelElementDrawPart((BarSeries)labelPart.Element, this);
             }
         }
     }
 }

 public class CustomLabelElementDrawPart : BarLabelElementDrawPart
 {
     public CustomLabelElementDrawPart(ChartSeries owner, IChartRenderer renderer)
         : base(owner, renderer)
     { }
     
     public override void Draw()
     {
         Graphics graphics = this.Renderer.Surface as Graphics;
         CartesianSeries cartesianSeries = this.Element as CartesianSeries;
         if (cartesianSeries != null)
         {
             CartesianArea area = (CartesianArea)cartesianSeries.GetType().GetField("area", BindingFlags.Instance | BindingFlags.NonPublic).GetValue(cartesianSeries);
             RectangleF clipRect = (RectangleF)area.GetType().GetMethod("GetCartesianClipRect", BindingFlags.Instance | BindingFlags.NonPublic).Invoke(area, new object[] { });//.GetCartesianClipRect();
             graphics.SetClip(clipRect);
         }

         base.Draw();

         graphics.ResetClip();
     }
 }

Workaround:

public class CustomLassoZoomController : LassoZoomController
{
    protected override ActionResult OnMouseUp(MouseEventArgs e)
    {
        if (this.MouseDownLocation == Point.Empty || this.MouseMoveLocation == Point.Empty)
        {
            return Controller.Empty;
        }

        return base.OnMouseUp(e);
    }
}

public Form1()
{
    InitializeComponent();

    BarSeries barSeries = new BarSeries("Performance", "RepresentativeName");
    barSeries.Name = "Q1";
    barSeries.DataPoints.Add(new CategoricalDataPoint(177, "Harley"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(128, "White"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(143, "Smith"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(111, "Jones"));
    barSeries.DataPoints.Add(new CategoricalDataPoint(118, "Marshall")); 
    this.radChartView1.Series.Add(barSeries);

    BarSeries barSeries2 = new BarSeries("Performance", "RepresentativeName");
    barSeries2.Name = "Q2";
    barSeries2.DataPoints.Add(new CategoricalDataPoint(153, "Harley"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(141, "White"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(130, "Smith"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(88, "Jones"));
    barSeries2.DataPoints.Add(new CategoricalDataPoint(109, "Marshall"));
    this.radChartView1.Series.Add(barSeries2);

    CustomLassoZoomController lassoZoomController = new CustomLassoZoomController();
    radChartView1.Controllers.Add(lassoZoomController);
}

Hello Telerik Support,

after taking my first steps with RangeSelector and ChartView controls I found an issue with a simple bar chart. The length of some bars in the chart of the RangeSelector doesn't match with the bars in the ChartView. The relation is wrong.I provided a screenshot and marked the bars. I could provide a sample application, but I can't attach a zip file, so here's the code of the main form:

Regards,

Stephan

To reproduce: please refer to the attached sample project and gif file.

Workaround: 
            CustomLassoSelectionController lassoSelectionController = new CustomLassoSelectionController(); 
            this.radChartView1.Controllers.Add(lassoSelectionController);

        public class CustomLassoSelectionController : LassoSelectionController
        {
            private IList<DataPoint> selectedPoints = null;

            public CustomLassoSelectionController()
            {
                this.selectedPoints = new List<DataPoint>();
            }

            private Point ClipLocation(Point point)
            {
                CartesianArea area = this.Area.View.GetArea<CartesianArea>();
                if (area != null)
                {
                    RectangleF clipRect = GetCartesianClipRect(area);

                    if (point.X < clipRect.X)
                    {
                        point = new Point((int)clipRect.X, point.Y);
                    }

                    if (point.X > clipRect.Width + clipRect.X)
                    {
                        point = new Point((int)clipRect.Width + (int)clipRect.X, point.Y);
                    }

                    if (point.Y < clipRect.Y)
                    {
                        point = new Point(point.X, (int)clipRect.Y);
                    }

                    if (point.Y > clipRect.Height + clipRect.Y)
                    {
                        point = new Point(point.X, (int)clipRect.Height + (int)clipRect.Y);
                    }
                }

                return point;
            }

            internal RectangleF GetCartesianClipRect(CartesianArea area)
            {
                float x1, x2, y1, y2;
                x1 = 0;
                y1 = 0;
                x2 = (float)area.View.Viewport.Right;
                y2 = (float)area.View.Viewport.Bottom;

                foreach (var axis in area.View.Axes)
                {
                    if (axis.AxisType == AxisType.First)
                    {
                        if (axis.Model.VerticalLocation == AxisVerticalLocation.Bottom)
                        {
                            y2 = Math.Min(y2, (float)axis.Model.LayoutSlot.Y);
                        }
                        else
                        {
                            y1 = Math.Max(y1, (float)axis.Model.LayoutSlot.Bottom);
                        }

                        x1 = Math.Min(x1, (float)axis.Model.LayoutSlot.X);
                        x2 = Math.Min(x2, (float)axis.Model.LayoutSlot.Right);
                    }
                    else
                    {
                        if (axis.Model.HorizontalLocation == AxisHorizontalLocation.Left)
                        {
                            x1 = Math.Max(x1, (float)axis.Model.LayoutSlot.Right);
                        }
                        else
                        {
                            x2 = Math.Min(x2, (float)axis.Model.LayoutSlot.X);
                        }

                        y1 = Math.Max(y1, (float)axis.Model.LayoutSlot.Y);
                        y2 = Math.Min(y2, (float)axis.Model.LayoutSlot.Bottom);
                    }
                }

                RectangleF result = new RectangleF((float)area.View.Viewport.X + x1, (float)area.View.Viewport.Y + y1, x2 - x1 + 1, y2 - y1 + 1);

                return result;
            }

            protected override ActionResult OnMouseUp(MouseEventArgs e)
            {
                if (e.Button != MouseButtons.Left || this.MouseDownLocation == Point.Empty || this.MouseMoveLocation == Point.Empty)
                {
                    return base.OnMouseUp(e);
                }

                if (MouseDownLocation != MouseMoveLocation)
                {
                    this.MouseMoveLocation = ClipLocation(e.Location);
                    CartesianArea area = this.Area.View.GetArea<CartesianArea>();

                    if (area != null)
                    {
                        this.selectedPoints.Clear();
                        RectangleF areaRect = RectangleF.Empty;
                        IChartView chartView = this.Area.View;
                        areaRect = GetCartesianClipRect(area);

                        Point topLeft = new Point(Math.Min(MouseDownLocation.X, e.X), Math.Min(MouseDownLocation.Y, e.Y));
                        Point lowerRight = new Point(Math.Max(MouseDownLocation.X, e.X), Math.Max(MouseDownLocation.Y, e.Y));
                        RectangleF lassoRect = new RectangleF(new PointF(topLeft.X - (float)chartView.PlotOriginX - area.View.Margin.Left, topLeft.Y - (float)chartView.PlotOriginY - area.View.Margin.Top), new SizeF(lowerRight.X - topLeft.X, lowerRight.Y - topLeft.Y));

                        foreach (var series in area.View.Series)
                        {
                            foreach (var dataPoint in series.DataPoints)
                            {
                                if (lassoRect.Contains(new PointF((float)dataPoint.LayoutSlot.Location.X, (float)dataPoint.LayoutSlot.Location.Y)))
                                {
                                    dataPoint.IsSelected = true;
                                    this.selectedPoints.Add(dataPoint);
                                }
                                else
                                {
                                    dataPoint.IsSelected = false;
                                }
                            }
                        }
                        
                        ChartDataPointsEventArgs changedArgs = new ChartDataPointsEventArgs(this.selectedPoints);
                        this.OnLassoSelectedPointsChanged(changedArgs);
                    }

                    MouseDownLocation = MouseMoveLocation = Point.Empty;
                }

                this.Result.ShouldInvalidate = true;
                return this.Result;
            }
        }

Steps to reproduce:
1. Create an instance of any chart series
2. Set the Palette property to a new/existing PaletteEntry instance with any colors 

Run the project and you will see an exception.

Steps to reproduce:
1. Add chart to a form.
2. Add two bar series with CombineMode set to Stack100
3. Add two data points to the series with values 0.0 and identical category
4. Run the project an you will see an exception.

How to reproduce:
Dim table As New DataTable()
table.Columns.Add("Name", GetType(String))
table.Columns.Add("X", GetType(Integer))
 
For i As Integer = 0 To 99
    table.Rows.Add($"User {i}", i)
Next
 
Dim series As New BarSeries()
series.DataSource = table
series.CategoryMember = "Name"
series.ValueMember = "X"
 
RadChartView1.Series.Add(series)
 
CType(RadChartView1.Area, CartesianArea).Orientation = Orientation.Horizontal
         
Dim panZoomController As New ChartPanZoomController()
panZoomController.PanZoomMode = ChartPanZoomMode.Vertical
RadChartView1.Controllers.Add(panZoomController)
 
RadChartView1.Zoom(1, 8)

Workaround: create a custom ChartPanZoomController
Dim panZoomController As New MyChartPanZoomController()
panZoomController.PanZoomMode = ChartPanZoomMode.Vertical
RadChartView1.Controllers.Add(panZoomController)

Public Class MyChartPanZoomController
    Inherits ChartPanZoomController

    Protected Overrides Function OnMouseMove(e As MouseEventArgs) As ActionResult

        Dim cartesianArea As CartesianArea = TryCast(Me.Area, CartesianArea)
        If cartesianArea Is Nothing Then
            Return MyBase.OnMouseMove(e)
        End If

        Dim panPoint As Point? = Me.GetType().BaseType.GetField("panPoint", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)

        If e.Button = MouseButtons.Left AndAlso panPoint.HasValue Then
            Dim offsetX As Double = Me.GetType().BaseType.GetField("offsetX", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)

            Dim currentOffsetX As Double = offsetX
            Dim defaultAxis As Axis = If(cartesianArea.Orientation = Orientation.Horizontal,
                                         Me.Area.GetType().GetMethod("GetDefaultFirstAxis", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me.Area, New Object() {}),
                                         Me.Area.GetType().GetMethod("GetDefaultSecondAxis", BindingFlags.Instance Or BindingFlags.NonPublic).Invoke(Me.Area, New Object() {}))

            If Me.PanZoomMode = ChartPanZoomMode.Horizontal OrElse Me.PanZoomMode = ChartPanZoomMode.Both Then
                currentOffsetX += (panPoint.Value.X - e.Location.X) * -1

                If currentOffsetX > 0 Then
                    currentOffsetX = 0
                End If

                If currentOffsetX < defaultAxis.Model.LayoutSlot.Width * (DirectCast(cartesianArea.View, IChartView).ZoomWidth - 1) Then
                    currentOffsetX = -defaultAxis.Model.LayoutSlot.Width * (DirectCast(cartesianArea.View, IChartView).ZoomWidth - 1)
                End If
            End If

            Dim offsetY As Double = Me.GetType().BaseType.GetField("offsetY", BindingFlags.Instance Or BindingFlags.NonPublic).GetValue(Me)
            Dim currentOffsetY As Double = offsetY
            If Me.PanZoomMode = ChartPanZoomMode.Vertical OrElse Me.PanZoomMode = ChartPanZoomMode.Both Then
                currentOffsetY += (panPoint.Value.Y - e.Location.Y) * -1

                If currentOffsetY > 0 Then
                    currentOffsetY = 0
                End If

                If currentOffsetY < -defaultAxis.Model.LayoutSlot.Height * (DirectCast(cartesianArea.View, IChartView).ZoomHeight - 1) Then
                    currentOffsetY = -defaultAxis.Model.LayoutSlot.Height * (DirectCast(cartesianArea.View, IChartView).ZoomHeight - 1)
                End If
            End If

            cartesianArea.View.Pan(currentOffsetX, currentOffsetY)
        End If

        Return Controller.Empty

    End Function

End Class

When trying to drill down PieChart on RadChartView the code throws exception.

Workaround: private void radChartView_Drill(object sender, DrillEventArgs e){    e.View.Parent = this.radChartViewUsers.ChartElement.Wrapper;    e.View.AreaType = ChartAreaType.Pie;    //do drill logic}

To reproduce:
Add Series and Axes to a RadChartView and a ChartPanZoomController. Zoom and pan a little, then clear all the series and axes and add new ones. Try to pan now.

To reproduce:

private void RadChartView1_LabelFormatting(object sender, ChartViewLabelFormattingEventArgs e)
{
    var dataPoint = e.LabelElement.DataPoint as CategoricalDataPoint;
    if (dataPoint != null)
    {
         e.LabelElement.IsVisible = false;
    }
}

Workaround:
private void RadChartView1_LabelFormatting(object sender, ChartViewLabelFormattingEventArgs e)
{
    var dataPoint = e.LabelElement.DataPoint as CategoricalDataPoint;
    if (dataPoint != null)
    {
        e.LabelElement.Text = "";
    
    }
}

To reproduce:

Have a RadButton and a RadChartView on a form. On button click use the following code:
private void GenerateSeries()
{
    LineSeries lineSeries = new LineSeries();
    lineSeries.DataPoints.Add(new CategoricalDataPoint(20, "Jan") { Label = "January" });
    lineSeries.DataPoints.Add(new CategoricalDataPoint(22, "Apr"));
    lineSeries.DataPoints.Add(new CategoricalDataPoint(12, "Jul"));
    lineSeries.DataPoints.Add(new CategoricalDataPoint(19, "Oct"));
    lineSeries.LegendTitle = "Line 1 ";
    this.Chart.Series.Add(lineSeries);
    lineSeries.BackColor = Color.Black;
    lineSeries.PointSize = new SizeF(15, 15);

    LineSeries lineSeries2 = new LineSeries();
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(18, "Jan"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(15, "Apr"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(17, "Jul"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(22, "Oct"));

    lineSeries2.LegendTitle = "Line 2 ";
    this.Chart.Series.Add(lineSeries2);
}

void RadButton_Click(object sender, EventArgs e)
{
    this.Chart.Series.Clear();
    this.GenerateSeries();
}


You will notice that the memory will not decrease after a few presses of the button.

Workaround:

Set the Provider of the LegendElement to null:

private void GenerateSeries()
{
    this.Chart.ChartElement.LegendElement.Provider = null;


    LineSeries lineSeries = new LineSeries();
    lineSeries.DataPoints.Add(new CategoricalDataPoint(20, "Jan") { Label = "January" });
    lineSeries.DataPoints.Add(new CategoricalDataPoint(22, "Apr"));
    lineSeries.DataPoints.Add(new CategoricalDataPoint(12, "Jul"));
    lineSeries.DataPoints.Add(new CategoricalDataPoint(19, "Oct"));
    lineSeries.LegendTitle = "Line 1 ";
    this.Chart.Series.Add(lineSeries);
    lineSeries.BackColor = Color.Black;
    lineSeries.PointSize = new SizeF(15, 15);

    LineSeries lineSeries2 = new LineSeries();
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(18, "Jan"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(15, "Apr"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(17, "Jul"));
    lineSeries2.DataPoints.Add(new CategoricalDataPoint(22, "Oct"));

    lineSeries2.LegendTitle = "Line 2 ";
    this.Chart.Series.Add(lineSeries2);
}

void Button_Click(object sender, EventArgs e)
{
    this.Chart.Series.Clear();
    this.GenerateSeries();
}

To reproduce:
            WaterfallSeries series = new WaterfallSeries();
            series.ShowLabels = true;

            series.DataPoints.Add(new WaterfallDataPoint(50000, false, false, "Beginning\nBalance"));
            series.DataPoints.Add(new WaterfallDataPoint(17000, false, false, "Jan"));
            series.DataPoints.Add(new WaterfallDataPoint(14000, false, false, "Feb"));
            series.DataPoints.Add(new WaterfallDataPoint(-12000, false, false, "Mar"));
            series.DataPoints.Add(new WaterfallDataPoint(69000, true, false, "Q1"));
            series.DataPoints.Add(new WaterfallDataPoint(-22000, false, false, "Apr"));
            series.DataPoints.Add(new WaterfallDataPoint(-18000, false, false, "May"));
            series.DataPoints.Add(new WaterfallDataPoint(500, false, false, "Jun"));
            series.DataPoints.Add(new WaterfallDataPoint(-30000, true, false, "Q2"));
            series.DataPoints.Add(new WaterfallDataPoint(39000, false, true, "Ending\nBalance"));
            this.radChartView1.Series.Add(series);

            CartesianGridLineAnnotation annotation1 = new CartesianGridLineAnnotation();
            annotation1.Label = "Annotation";
            annotation1.ForeColor = Color.Lime;
            annotation1.BackColor = Color.Black;
            this.radChartView1.Annotations.Add(annotation1);

Workaround:

        public RadForm1()
        {
            InitializeComponent();
            this.radChartView1.CreateRenderer += radChartView1_CreateRenderer;

            WaterfallSeries series = new WaterfallSeries();
            series.ShowLabels = true;
     
            series.DataPoints.Add(new WaterfallDataPoint(50000, false, false, "Beginning\nBalance"));
            series.DataPoints.Add(new WaterfallDataPoint(17000, false, false, "Jan"));
            series.DataPoints.Add(new WaterfallDataPoint(14000, false, false, "Feb"));
            series.DataPoints.Add(new WaterfallDataPoint(-12000, false, false, "Mar"));
            series.DataPoints.Add(new WaterfallDataPoint(69000, true, false, "Q1"));
            series.DataPoints.Add(new WaterfallDataPoint(-22000, false, false, "Apr"));
            series.DataPoints.Add(new WaterfallDataPoint(-18000, false, false, "May"));
            series.DataPoints.Add(new WaterfallDataPoint(500, false, false, "Jun"));
            series.DataPoints.Add(new WaterfallDataPoint(-30000, true, false, "Q2"));
            series.DataPoints.Add(new WaterfallDataPoint(39000, false, true, "Ending\nBalance"));
            this.radChartView1.Series.Add(series);
 
            CartesianGridLineAnnotation annotation1 = new CartesianGridLineAnnotation();
            annotation1.Label = "Annotation";
            annotation1.ForeColor = Color.Lime;
            annotation1.BackColor = Color.Black;
            annotation1.PositonOffset = new SizeF(0, -20);
            annotation1.Axis = this.radChartView1.Axes[1] as CartesianAxis;
            annotation1.Value = 70000;
            annotation1.BorderColor = Color.Red;
            annotation1.BorderDashStyle = DashStyle.Solid;
            annotation1.BorderWidth = 1;
            this.radChartView1.Annotations.Add(annotation1);
        }

        private void radChartView1_CreateRenderer(object sender, ChartViewCreateRendererEventArgs e)
        {
            e.Renderer = new CustomCartesianRenderer(e.Area as CartesianArea);
        }
 
        public class CustomCartesianRenderer : CartesianRenderer
        {
            public CustomCartesianRenderer(CartesianArea area) : base(area)
            {
            }
 
            protected override void Initialize()
            {
                base.Initialize();
                for (int i = 0; i <= this.DrawParts.Count - 1; i++)
                {
                    CartesianGridLineAnnotationDrawPart annotationPart = this.DrawParts[i] as CartesianGridLineAnnotationDrawPart;
                    if (annotationPart != null)
                    {
                        this.DrawParts[i] = new CustomCartesianGridLineAnnotationDrawPart((CartesianGridLineAnnotation)annotationPart.Element, this);
                    }
                }
            }
        }

        public class CustomCartesianGridLineAnnotationDrawPart : CartesianGridLineAnnotationDrawPart
        {
            public CustomCartesianGridLineAnnotationDrawPart(CartesianGridLineAnnotation element, CartesianRenderer renderer) : base(element, renderer)
            {
            }

            public override void Draw()
            {
                FieldInfo fi = typeof(CartesianGridLineAnnotation).GetField("model", BindingFlags.NonPublic | BindingFlags.Instance);
                ChartAnnotationModel model = fi.GetValue(this.Element) as ChartAnnotationModel;
                RectangleF
                rect = ChartRenderer.ToRectangleF(model.LayoutSlot);
                rect.Offset(this.ViewportOffsetX, this.ViewportOffsetY);

                Graphics graphics = this.Renderer.Surface as Graphics;
                RadGdiGraphics radGraphics = new RadGdiGraphics(graphics);

                Rectangle clipRect = ChartRenderer.ToRectangle(this.Element.View.GetArea<CartesianArea>().AreaModel.PlotArea.LayoutSlot);
                clipRect.Offset((int)this.ViewportOffsetX, (int)this.ViewportOffsetY);
                graphics.SetClip(clipRect);

                GraphicsPath path = new GraphicsPath();
                path.AddLine(rect.Location, new PointF(rect.Right, rect.Bottom));

                BorderPrimitiveImpl border = new BorderPrimitiveImpl(this.Element, null);
                border.PaintBorder(radGraphics, null, path, rect);

                rect.Size = graphics.MeasureString(this.Element.Label, this.Element.Font);
                rect.Offset(this.Element.PositonOffset.Width + 1, this.Element.PositonOffset.Height + 1);

                TextParams tp = new TextParams();
                tp.font = this.Element.Font;
                tp.foreColor = this.Element.ForeColor;
                tp.paintingRectangle = rect;
                tp.text = this.Element.Label;

                FillPrimitiveImpl fill = new FillPrimitiveImpl(this.Element, null);
                fill.PaintFill(radGraphics, null, rect);
            
                TextPrimitiveHtmlImpl text = new TextPrimitiveHtmlImpl();
                text.PaintPrimitive(radGraphics, 0f, new SizeF(1f, 1f), tp);
            }
        }

How to reproduce: explicitly set the border color of the series

Workaround:
public partial class Form1 : Form
{
    private RangeSelectorViewElement chartElement;

    public Form1()
    {
        InitializeComponent();

        LineSeries lineSeries = new LineSeries();
        lineSeries.Name = "Line";
        lineSeries.BorderColor = Color.Green;
        lineSeries.DataPoints.Add(new CategoricalDataPoint(20, "Jan"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(22, "Apr"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(12, "Jul"));
        lineSeries.DataPoints.Add(new CategoricalDataPoint(19, "Oct"));
        this.radChartView1.Series.Add(lineSeries);

        this.chartElement = this.radRangeSelector1.RangeSelectorElement.AssociatedElement as RangeSelectorViewElement;
        this.chartElement.SeriesInitialized += ChartElement_SeriesInitialized;
    }

    private void ChartElement_SeriesInitialized(object sender, SeriesInitializedEventArgs e)
    {
        if (e.Series.Name == "Line")
        {
            e.Series.BorderColor = this.radChartView1.Series.Where(s => s.Name == "Line").First().BorderColor;
        }
    }
}

Use LogarithmicAxis and set the Minimum to 0.1

Workaround is availble in the atched project.