ASP DropDownList UpdatePanel IE JS Errors

Question

I'm getting a peculiar javascript error with IE. I have an updatepanel, and inside it a drop down list. When I change the dropdownlist's value, it gives me error "Line: 5 '__EVENTTARGET' is null or not an object'. I took a look, and this Line 5 and __EVENTTARGET are in the ASP.NET generated javascript code.

I want a dropdownlist that fires method when new option selected, with no page flicker.

Here's some of my code :

<asp:ScriptManager ID="uxScriptMan" runat="server" />
<asp:UpdatePanel ID="uxtestupdatepanel" runat="server">
<ContentTemplate>
<asp:DropDownList ID="DropDownList1" runat="server" 
    AutoPostBack="true" OnSelectedIndexChanged="TESTMETHOD">
 <asp:ListItem Text="TEST" Selected="true" />
 <asp:ListItem Text="Yes" Value="1" />
 <asp:ListItem Text="No" Value="0" />
</asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>

and

protected void TESTMETHOD(object sender, EventArgs e) { /*do nothing*/ }

In Firefox, it works, no errors. And in fact, on dev machine, uncompiled soln with .aspx and .aspx.cs files, no errors in IE. On production machine, compiled, I get IE js errors.

Whats the problem, how do i fix, or at least, where can I start looking? Done a ton of googling with not much luck.

Answer 1

Fixed it! It was a combination of Duck and ck's comments.

Thanks guys.

It was a web.config problem. This particular application's web.config was different from a few other applications we had been using on our servers. Here's the fixes for anyone else who ever has this problem.

Incorrect web.config:

<compilation debug="false">
        <assemblies>
            <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
            <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
        </assemblies>
    </compilation>


 <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
        <dependentAssembly>
            <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
            <bindingRedirect oldVersion="1.0.61025.0" newVersion="3.5.0.0"/>
        </dependentAssembly>
    </assemblyBinding>
</runtime>

Correct web.config:

<compilation debug="false">
  <assemblies>
    <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Web.Extensions.Design, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
  </assemblies>

Answer 2

A shot in the dark, does your server have the same service packs as your development environment?

If you're using .NET 3.5 SP1, the service pack makes a big difference and could account for the odd discrepancy.

Answer 3

Do you have the same web.config in both? Your production one may be missing the resource handler for ScriptResource.axd

Answer 4

Try setting the ScriptManager EnablePartialRendering property

EnablePartialRendering="false"

And see if you still get an error

Also try turning off event validation on that page

<%@ Page EnableEventValidation="false" %>

And see if you still get an error