I have an interesting viewstate problem here that I’m having trouble ironing out. Granted

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Asked: May 18, 20262026-05-18T11:46:37+00:00 2026-05-18T11:46:37+00:00

I have an interesting viewstate problem here that I’m having trouble ironing out. Granted

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I have an interesting viewstate problem here that I’m having trouble ironing out. Granted I’m not an expert at dealing with the viewstate, it is probably one of the most confusing theings about .NEt but that is neither here no there. Here is the error I’m getting.

Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request.

What is weird about this is that it only happens on the homepage of the site (code is located in footer of master page). Every other page on the site it works fine. Here is the aspx code. Note this is in the footer of the master file.

<asp:UpdatePanel ID="upEmail" runat="server" >
  <ContentTemplate>
    <asp:MultiView ID="mview" runat="Server" ActiveViewIndex="0">

      <asp:View ID="viewInput" runat="Server">
        <div>
          <asp:Panel ID="pnlEmail" runat="server" DefaultButton="btnSubscribe" Width="100%" EnableViewState="False">
            <asp:TextBox ID="tbEmail" runat="server" Width="125px" CssClass="someClass" title="Enter Your Email Address" />
            <ajaxToolkit:TextBoxWatermarkExtender ID="TextBoxWatermarkExtender1" TargetControlID="tbEmail" WatermarkText="Email Address" runat="server" />
            <asp:RequiredFieldValidator ID="rfEmail" runat="Server" ControlToValidate="tbEmail" ValidationGroup="submit">*</asp:RequiredFieldValidator>
            <asp:ImageButton ID="btnSubscribe" ImageUrl="/Images/social/signup.gif" Imagealign="absmiddle" runat="server" OnClick="BtnSubscribe_Clicked" ValidationGroup="submit" />
            <br />
            <asp:RegularExpressionValidator ID="regEmail" runat="server" ControlToValidate="tbEmail" ErrorMessage="Please enter a valid email." ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*" ValidationGroup="submit" Display="dynamic" ForeColor="" CssClass="error_font_no_hover" />
          </asp:Panel>
        </div>
        <div>
          <asp:Label ID="lblMessage" runat="server" Visible="false" />
        </div>
      </asp:View>

      <asp:View ID="viewSuccess" runat="server">
        Thank You! You will now
        <br />
        receive e-mails!
      </asp:View>

    </asp:MultiView>
  </ContentTemplate>
</asp:UpdatePanel>

I’ve tried disabling the viewstate on the panel and the error still occurs. Can anyone tell me what is going on?

Thank You in advance