I found a document online that tells me:
...
The reason for this error is that your grid instance can not bind a value for the newly inserted item through the Eval()/Bind() syntax you hard-coded (as you may have seen from the stack trace of the error).

This problem can be fixed in the following ways:

• preset the default value of the control(s) when binding to a grid item on the RadGrid.InitInsertCommandName command.

...

Here is the code I have in my NestedViewTemplate:
                                     <asp:DropDownList ID="cboLanguage" runat="server" DataSourceID="dsLanguage" DataTextField="Text"
                                            DataValueField="value" SelectedValue='<%# Bind("LanguageID") %>' AppendDataBoundItems="True"  >
                                            <asp:ListItem Value="-1">Please Select</asp:ListItem>
                                        </asp:DropDownList>
                                        <asp:ObjectDataSource ID="dsLanguage" runat="server" SelectMethod="FetchEntries"
                                            TypeName="BenemTech.SHSR_DonorMgmt.DAO.ListDAO">
                                            <SelectParameters>
                                                <asp:Parameter DefaultValue="Language" Name="GroupName" Type="String" />
                                            </SelectParameters>
                                        </asp:ObjectDataSource>

So the problem described makes a little sense, but I have no idea how to do what the document suggests.
I am using VS 2010 and simply can't find this InitInsertCommandName method or property or event

Can somebody please post simple code that would go in this event (once I find it) to make this work?

Thanks in advance.



I am willing to try this (not sure why it matters though) but