If you programmatically set the GroupColumnDescriptions for the grid in the drop down like this:
sfddControl.GetDropDownGrid().GroupColumnDescriptions.Add(new GroupColumnDescription { ColumnName="Column1Text" });
When you click an item inside of a group it will throw this exception:
"System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.\rParameter name: index\r at System.ThrowHelper.ThrowArgumentOutOfRangeException()\r at System.Collections.Generic.List`1.get_Item(Int32 index)\r at System.Collections.ObjectModel.Collection`1.get_Item(Int32 index)\r at Syncfusion.Data.RecordsEntryList.get_Item(Int32 index)\r at Syncfusion.Data.TraversalHelper.GetPrevious(NodeEntry entry)\r at Syncfusion.Data.GroupDisplayElem" string
but if you set the style and add in the GroupColumnDescriptions using XAML it works fine.
