I got a red border around the grid when row is selected.
This reminds me behavior when data source implements IDataErrorInfo end some errors are there. But my data source is just an ObservableCollection<T> and data items are my custom class that doesn't implement IDataErrorInfo. The only thing is that some of the data items properties type is my custom type. What could it be and how can I get rid of this border?
My mistake. Just found that ActiveDataItem property was bound to the property with different type than data item type.