Ya verificaste que tengas tus controles dentro del form..??
Cita: <
form id="form1" runat=server>
...
<asp:Label id="Label1" runat="server">Label</asp:Label>
</p>
<p>
<asp:TextBox id="TextBox1" runat="server"></asp:TextBox>
<asp:Button id="Button1" onclick="Button1_Click" runat="server" Text="Button"></asp:Button>
...
</
form>
Salu2