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

script = " var oExplorer = $find('" + RadFileExplorer1.ClientID + "');" +

" oExplorer.set_currentDirectory('" + dir + "');" +

" oExplorer.refresh();";

<ResourceHeaderTemplate>

                    <asp:Panel ID="ResourceWrapper" runat="server" CssClass="ResCustomClass">

                        <asp:Table ID="ResourceTable" runat="server" Width="200px">

                            <asp:TableRow Width="200px">

                                <asp:TableCell Width="95px" HorizontalAlign="Right">

                                    <asp:Label ID="LGroup" Font-Bold="true" runat="server" Text='<%# Eval("resgroup") %>'></asp:Label>

                                </asp:TableCell>

                                <asp:TableCell HorizontalAlign="Center" Width="10px">

                                    <asp:Label ID="LSpacer" runat="server" Text="|"></asp:Label>

                                </asp:TableCell>

                                <asp:TableCell  Width="95px" HorizontalAlign="Right">

                                    <asp:Label ID="SpeakerImage" runat="server" Text='<%# Eval("Text") %>'></asp:Label>

                                </asp:TableCell>

                            </asp:TableRow>

                        </asp:Table>

                    </asp:Panel>

                </ResourceHeaderTemplate>