lusty_learner

<asp:TemplateField HeaderText="Client Name" SortExpression="Client.Name"> <ItemTemplate> <asp:Label ID="ClientNameLabel" Text='<%#Eval("Client.Name") %>' runat="server" /> </ItemTemplate> </asp:TemplateField>

This is invalid notation.  I suggest creating a property called ClientName that defines a getter, which returns the Client.Name value.