1. Change the view from BarSeries to Pie Series
     => Observe the PieChart loads as expected
2. Change the selection back to "Bar Series"
     => Observe BarSeries continues to operate as expected
3. Change the selection from "Bar Series" to "Pie Series"
     => Observe the following exception

Java.Lang.NullPointerException: 'Attempt to read from field 'double com.telerik.widget.chart.visualization.pieChart.PieUpdateContext.radius' on a null object reference'

Workaround: 
Remove the ShowLabels from Pie Series.