or
<telerik:GridViewDataColumn x:Name="RequestedQty" DataMemberBinding="{Binding RequestedQty, StringFormat='n'}" Header="Req Qty" Width="75" TextAlignment="Right" HeaderTextAlignment="Right" TabStopMode="{Binding StepIsReadOnly, Converter={StaticResource BooleanToTabStopModeConverter}}"/>System.Windows.Data Error: 40 : BindingExpression path error: 'StepIsReadOnly' property not found on 'object' ''BatchFixDataEntryViewModel' (HashCode=24249959)'. BindingExpression:Path=StepIsReadOnly; DataItem='BatchFixDataEntryViewModel' (HashCode=24249959); target element is 'GridViewDataColumn' (HashCode=19523191); target property is 'TabStopMode' (type 'GridViewTabStop')