title: Section or group name 'cachingConfiguration' is already defined - but where?
body: <p>On Windows XP I am working on a .NET 3.5 web app that's a combination of WebForms and MVC2 (The WebForms parts are legacy, and being migrated to MVC). When I run this from VS2008 using the ASP.NET web server everything works as expected.</p>
  
  <p>However, when I host the app in IIS and try to use it, I see the following error</p>
  
  <pre>Section or group name 'cachingConfiguration' is already defined.
  Updates to this may only occur at the configuration level where it is defined.
  
  Source Error: 
  Line 24:     &lt;/sectionGroup&gt;
  Line 25:     &lt;section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net"/&gt;
  Line 26:     &lt;section name="cachingConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Caching.Configuration.CacheManagerSettings,Microsoft.Practices.EnterpriseLibrary.Caching, Version=4.1.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /&gt;
  Line 27:   &lt;/configSections&gt;
  Line 28: </pre>
  
  <p>Sure enough, if I remove the offending line (line 26 in the error message) from my web.config then the app runs correctly.</p>
  
  <p>However, I really need to find out where the duplicate definition of this is. It's nowhere in my solution. Where else could it be?</p>
  
  <h2>Edit</h2>
  
  <p>Some additional information:</p>
  
  <p>This is the only application I'm working on, so rather than add a virtual directory in IIS I've simply repointed the local path of the Default Web Site to point at my site.</p>