The designer crashes with this exception:
InvalidOperationException: 'GridViewColumnGroupRow' TargetType does not match type of element 'GridViewColumnGroupRow'.

See the attached screenshot. It's from a new project, after clean and rebuild.

Visual studio: 2015
Telerik UI for wpf: 2015.2
Implicit styles, Windows8 theme.

* The problem is not theme specific. As a workaround, use no xaml binaries instead of xaml files.

GridViewHeaderCell are not draggable when RadGridView is hosted in DropDownButton.DropDownContent. Trying to drag a cell does not trigger drag events.

The problem should be resolved with lib version 2015.3.1012.

I would like to be bale to modify at once several cells of a GridViewComboBoxColumn, when using the common ItemsSourceBinding for all rows (in my GridView, the selection ​is: SelectionMode="Multiple" SelectionUnit="FullRow").
So I would like for the selected rows to apply the same value as the edited cell.

The issue is reproduced only with GroupRenderMode="Flat".

GridViewDataColumn doesn't respect FallbackValue when the source property returns DependencyProperty.UnsetValue

The problem should be resolved with lib version 2015.3.1130.

With R2 2016 GridViewComboBoxColumn will expose a property IsLightweightModeEnabled. Setting the property to True should resolve the problem.

The problem should be resolved with lib version 2016.1.125.

If I change Column.IsVisibility to FALSE, the column group headers are disappear and not restored.

The problem should be resolved with LIB version 2016.1.404.

This functionality will be available with Q1 2016 SP.