System.Windows.Data Error: 5 : Value produced by BindingExpression is not valid for target property.; Value='<null>' BindingExpression:Path=RentStartDateFilter; DataItem='CarRentalViewModel' (HashCode=46888886); target element is 'DatePicker' (Name=''); target property is 'DisplayDate' (type 'DateTime')
System.Windows.Data Error: 5 : Value produced by BindingExpression is not valid for target property.; Value='<null>' BindingExpression:Path=RentEndDateFilter; DataItem='CarRentalViewModel' (HashCode=46888886); target element is 'DatePicker' (Name=''); target property is 'DisplayDate' (type 'DateTime')