Q:

ASP.NET CompositeScript Path results in 404

If I use the CompositeScript feature of the ASP.NET ScriptManager/ScriptManagerProxy controls, I cannot get the Path attribute to work:
My code
<asp:ScriptManagerProxy ID="scriptProxy2" runat="server">
  <CompositeScript Path="~/Includes/Javascript/Combined.js">
    <Scripts>
      <asp:ScriptReference Path="~/Includes/Javascript/MyFile1.js" />
      <asp:ScriptReference Path="~/Includes/Javascript/MyFile2.js" />
    </Scripts>
  </CompositeScript>
</asp:ScriptManagerProxy>

My page gets the correct script tag in it:
<script src="../Includes/Javascript/Combined.debug.js" type="text/javascript"></script>

But of course, that file doesn't exist and so the browser gets a 404.
Am I missing something?

A:

Have you specified source scripts to get combined using ScriptReference tag - see the documentation. 
EDIT: After using reflector, I discovered that if you use specify Path attribute, the script combining does not happen - it just emits script ref to the path specified (modifying as per release/debug mode and culture (if localization is enabled)). After googling around, found that intended use of path property is to work around url limit of 1024 characters. From this MSDN documentation:

The number of script references that a
  CompositeScriptReference instance can
  contain is limited by the size of the
  resulting URL. The URL cannot be
  longer than 1024 characters.
If you have to work around this
  limitation, you have two options. The
  first option is to reduce the number
  of ScriptReference objects that the
  composite script contains. The second
  option is to manually combine the
  scripts into a single static file. In
  that case, you can set the Path
  property to the location of the static
  file.

I have also stumbled upon this link where there is a wealth of information in comments section. One such comment clearly states that

You can combine multiple physical
  script files using that feature, but
  we really don't recommend it as there
  is some server overhead related to
  file monitoring. What you're
  describing is much better handled by
  "building" your scripts at compile
  time instead of doing the combination
  at runtime. The feature really is for
  application developers who want to
  combine existing scripts from various
  components that they use in their
  application.

So in summary, I think that how you intend use the combine script is neither supported nor recommended. I will suggest that you use build time script combining - below resources will help you in achieving the same:
http://encosia.com/2009/05/20/automatically-minify-and-combine-javascript-in-visual-studio/
Look at mashing feature in Chirpy add-in: http://www.weirdlover.com/2010/07/18/chirpy-attains-godlike-abilities-in-version-1-0-0-4/#mash

