Infragistics WebDataGrid Checkbox checked then page change = Async req failed

I have a webdatagrid with column 0 as a check box.

<Columns>
    <ig:UnboundCheckBoxField Key="Checked" Header-Text="Select" Width="50" HeaderCheckBoxMode="BiState">
    <Header Text="Select"></Header>
    </ig:UnboundCheckBoxField>
</Columns>

And the column is editable:

<ig:CellEditing>
    <ColumnSettings>
    <ig:EditingColumnSetting ColumnKey="Checked" />
    </ColumnSettings>
</ig:CellEditing>

All works fine but when I check a few and go to another page i.e. 2 then it throws an Async error as seen in the attached image.

When the column check box to check all is checked then all are checked and I can go to the second page and those all are selected as well. However, not when all exclusive.

Well, the stack trace tells everything in this case.
You should set the DataKeyFields property.
Just before the there is the template for your WebDataGrid, look for the DataKeyFields.
It should reference the primary key of your table

    <ig:WebDataGrid 
        ID="wdg" 
        runat="server" 
        DataKeyFields="Id"   <-- change with your primary key
        Width="400">
        <Columns>
            <ig:UnboundCheckBoxField Key="Checked" Header-Text="Select" Width="50" headerCheckBoxMode="BiState">
            <Header Text="Select"></Header>
            </ig:UnboundCheckBoxField>
        </Columns>