Thank you for your tutorial in video, unfortunately it still does not work for me because my Grid is binding with dynamic data table which I have no idea how many columns or the name of the columns it may contain, in your demo you have columns defined in Page(.aspx), however, my grid would be more like below:
<telerik:RadGrid ID="RadGrid1" runat="server" OnNeedDataSource="RadGrid1_NeedDataSource"
<MasterTableView Name="Main" CellPadding="0" CellSpacing="0" NoMasterRecordsText="" ></MasterTableView>
Like I said, if I defined columns in Page(.aspx), FilterCheckListEnableLoadOnDemand = "true" and FilterCheckListEnableLoadOnDemand would work perfectly but if I don't define any columns, it won't work.
Could you please try with a grid that has no columns defined(both master table and detail table) in Page and see?
Thank you very much for your help!