To reproduce: -add RadChartView and use the following code: public Form1() { InitializeComponent(); radChartView1.SelectionMode = ChartSelectionMode.MultipleDataPoints; MessageBox.Show(radChartView1.SelectionMode.ToString()); radChartView1.SelectionMode = ChartSelectionMode.MultipleDataPoints; MessageBox.Show(radChartView1.SelectionMode.ToString()); }