Not too sure which example your looking at as only partial url.

Are you binding the chart to a DataTable or creating a custom series?
Did you add the chart with the Chart Wizard?
Also, is there any data in the chart? 
Is the legend drawn but there is no series data in it?

This should display the legend:

ultraChartData.Legend.Visible =

True

But you may have to add it manually with something like as follows for composite charts:

Dim

myLegend As New CompositeLegend()

myLegend.ChartLayers.Add(cla)

myLegend.Bounds = New System.Drawing.Rectangle(1, 83, 25, 17)
myLegend.BoundsMeasureType = Infragistics.UltraChart.Shared.Styles.MeasureType.Percentage
myLegend.PE.ElementType = Infragistics.UltraChart.Shared.Styles.PaintElementType.Gradient
myLegend.PE.FillGradientStyle = Infragistics.UltraChart.Shared.Styles.GradientStyle.Horizontal
myLegend.PE.Fill = System.Drawing.Color.Transparent
myLegend.PE.FillStopColor = System.Drawing.Color.Transparent

myLegend.Border.Thickness = 0

You will need to add each chart layer to the legend manually in the highlighted code.