ASP.NET Performance Profiling 404/500 errors

Question

Using the Visual Studio Performance Explorer, with Cassini, I'm trying to launch profiling on my (Orchard CMS 1.4.0) ASP.NET MVC3 application, but I get this error:

The web site could not be configured correctly; getting ASP.NET process information failed. Requesting http://localhost:30320/OrchardLocal/VSEnterpriseHelper.axd returned an error: The remote server returned an error: (404) Not Found.

So I searched for a solution and found this article which didn't apply, because I'm using Visual Studio's development server (Cassini) not IIS - no less IIS 6. Then I read this article and this article; of all those suggestions, the only one that made a difference was adding the location section to my web.config, to grant access to VSEnterpriseHelper.axd. But as one of those articles predicted, my 404 error simply became a 500:

The web site could not be configured correctly; getting ASP.NET process information failed. Requesting http://localhost:30320/OrchardLocal/VSEnterpriseHelper.axd returned an error: The remote server returned an error: (500) Internal Server Error.

The trailing commentaries in these various articles aren't working for me. Any suggestions? I figure I will post my (Orchard 1.4.0) web.config here, in case somebody can spot a culprit:

<?xml version="1.0"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>
  <configSections>
    <sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor">
      <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor" requirePermission="false" />
      <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor" requirePermission="false" />
    </sectionGroup>

    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler, log4net" requirePermission="false" />
  </configSections>

  <appSettings>
    <add key="webpages:Enabled" value="false" />
    <add key="log4net.Config" value="Config\log4net.config" />
  </appSettings>

  <!-- Added this, which eliminated the profiling 
  VSEnterpriseHelper.axd 404 error - and led to a 500 
  error instead. -->
  <location path="VSEnterpriseHelper.axd">
    <system.web>
      <authorization>
        <allow users="*"/>
      </authorization>
    </system.web>
  </location>

  <system.web.webPages.razor>
    <host factoryType="System.Web.Mvc.MvcWebRazorHostFactory, System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
    <pages pageBaseType="Orchard.Mvc.ViewEngines.Razor.WebViewPage">
      <namespaces>
        <add namespace="System.Web.Mvc" />
        <add namespace="System.Web.Mvc.Ajax" />
        <add namespace="System.Web.Mvc.Html" />
        <add namespace="System.Web.Routing" />
        <add namespace="System.Web.WebPages" />
        <add namespace="System.Linq"/>
        <add namespace="System.Collections.Generic"/>
        <add namespace="Orchard.Mvc.Html"/>
      </namespaces>
    </pages>
  </system.web.webPages.razor>

  <!-- 
        Set default transaction timeout to 30 minutes so that interactive debugging 
        is easier (default timeout is less than one minute)
  -->
  <system.transactions>
    <defaultSettings timeout="00:30:00"/>
  </system.transactions>
  <system.web>
    <!--<trust level="Medium" originUrl="" />-->

    <httpRuntime requestValidationMode="2.0" />
    <!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.
    -->
    <compilation debug="true" targetFramework="4.0" batch="true" numRecompilesBeforeAppRestart="250" optimizeCompilations="true">
        <buildProviders>
        <add extension=".csproj" type="Orchard.Environment.Extensions.Compilers.CSharpExtensionBuildProviderShim"/>
      </buildProviders>
      <assemblies>
        <add assembly="System.Web.Mvc, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL"/>
        <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL"/>
        <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL"/>
        <add assembly="System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <remove assembly="System.Configuration, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <remove assembly="System.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <remove assembly="System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.Web.Services, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <remove assembly="System.Xml, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <remove assembly="System.EnterpriseServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        <remove assembly="System.IdentityModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.Runtime.Serialization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.ServiceModel, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.ServiceModel.Activation, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <remove assembly="System.ServiceModel.Web, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <remove assembly="System.Activities, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <remove assembly="System.ServiceModel.Activities, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <remove assembly="System.WorkflowServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
        <remove assembly="System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
        <remove assembly="System.Data.DataSetExtensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
        <remove assembly="System.Web.ApplicationServices, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
      </assemblies>
    </compilation>
    <!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
    -->
    <authentication mode="Forms">
      <forms loginUrl="~/Users/Account/AccessDenied" timeout="2880"/>
    </authentication>

    <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.
    -->
    <customErrors mode="RemoteOnly" />
    <pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
      <namespaces>
        <add namespace="System.Web.Mvc"/>
        <add namespace="System.Web.Mvc.Ajax"/>
        <add namespace="System.Web.Mvc.Html"/>
        <add namespace="System.Web.Routing"/>
        <add namespace="System.Linq"/>
        <add namespace="System.Collections.Generic"/>
        <add namespace="Orchard.Mvc.Html"/>
      </namespaces>
    </pages>

    <httpHandlers>
      <!-- see below -->
      <clear />
      <add path="*" verb="*" type="System.Web.HttpNotFoundHandler"/>

    </httpHandlers>

    <httpModules>
      <add name="WarmupHttpModule" type="Orchard.WarmupStarter.WarmupHttpModule, Orchard.WarmupStarter, Version=1.0.20, Culture=neutral"/>
    </httpModules>
  </system.web>

  <!-- 
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
  -->
  <system.webServer>

    <validation validateIntegratedModeConfiguration="false" />
    <modules runAllManagedModulesForAllRequests="true">
      <remove name="WarmupHttpModule" />
      <add name="WarmupHttpModule" type="Orchard.WarmupStarter.WarmupHttpModule, Orchard.WarmupStarter, Version=1.0.20, Culture=neutral"/>
    </modules>
    <handlers accessPolicy="Script">
      <!-- clear all handlers, prevents executing code file extensions, prevents returning any file contents -->
      <clear/>
      <!-- Return 404 for all requests via managed handler. The url routing handler will substitute the mvc request handler when routes match. -->
      <add name="NotFound" path="*" verb="*" type="System.Web.HttpNotFoundHandler" preCondition="integratedMode" requireAccess="Script"/>
    </handlers>
    <!-- Prevent IIS 7.0 from returning a custom 404/500 error page of its own -->
    <httpErrors existingResponse="PassThrough" />
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <probing privatePath="App_Data/Dependencies"/>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0" newVersion="3.0.0.0"/>
        <bindingRedirect oldVersion="2.0.0.0" newVersion="3.0.0.0"  />
      </dependentAssembly> 
    </assemblyBinding>
  </runtime>
</configuration>

Answer 1

In my case, I had

    <validation validateIntegratedModeConfiguration="true" />

set in my web.config. When I changed it to

    <validation validateIntegratedModeConfiguration="false" />

things magically started working. Three hours down the drain....

Answer 2

I faced similiar problem, and I found one solution. I found out that I get 404 error because VSEnterpriseHelper.axd is routed through MVC, and it's happening whatever I set in Web.config. So I figured out that I should route it properly. So I added route to handle this file, and I wrote handler:

Handler:

public class DefaultRouteHandler : IRouteHandler
{
    public IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        return new DefaultHttpHandler();
    }
}

internal class DefaultHttpHandler : IHttpHandler, IRequiresSessionState
{
    public void ProcessRequest(HttpContext context)
    {
        string contentPath = context.Request.PhysicalPath;

#if DEBUG
        if (contentPath == context.Server.MapPath("VSEnterpriseHelper.axd"))
        {
            var assembly = AppDomain.CurrentDomain.GetAssemblies().SingleOrDefault(a => a.GetName().Name == "Microsoft.VisualStudio.Enterprise.AspNetHelper");
            if (assembly == null)
            {
                if (File.Exists(@"C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies\Microsoft.VisualStudio.Enterprise.AspNetHelper.dll"))
                {
                    assembly = Assembly.LoadFrom(@"C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies\Microsoft.VisualStudio.Enterprise.AspNetHelper.dll");
                }
                if (File.Exists(@"C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies\Microsoft.VisualStudio.Enterprise.AspNetHelper.dll"))
                {
                    assembly = Assembly.LoadFrom(@"C:\Program Files\Microsoft Visual Studio 10.0\Common7\IDE\PrivateAssemblies\Microsoft.VisualStudio.Enterprise.AspNetHelper.dll");
                }
            }
            var type = assembly.GetType("Microsoft.VisualStudio.Enterprise.Common.AspNetHelperHandler");
            var handler = (IHttpHandler)Activator.CreateInstance(type);

            handler.ProcessRequest(context);
            return;
        }
#endif
        [...]
    }   
}

Route definition:

DefaultRouteHandler defaultHandler = new DefaultRouteHandler();
routes.Add(new Route("{*resource}", new RouteValueDictionary(), new RouteValueDictionary(), defaultHandler));

Answer 3

I fixed the same 500 error, here is what you need to do (partially borrowed from here with my own comment):

• Make sure you have write permissions on your web.config file

• If your website has locked down security on the root folder (using either forms or windows authentication etc), make sure you add a [location] tag to allow full access to the vsenterprisehelper.axd file, like this:

  <location path="VSEnterpriseHelper.axd">
      <system.web>
          <authorization>
              <allow users="?" />
          </authorization>
      </system.web>
  </location> 
  

• Ensure AXD extensions are configured in IIS for your site

• There are problems if your AppSettings are stored in a separate configuration file, and your web.config refers to them with a configSource attribute

Answer 4

I finally (4 hours later) fixed this by moving my default .axd route handler from RouteConfig.cs into the main Global.asax.cs:

AreaRegistration.RegisterAllAreas();
// Register .axd route ahead of WebApiConfig
RouteTable.Routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
GlobalConfiguration.Configure(WebApiConfig.Register);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);

Because I was using WebAPI, the WebApiConfig routes were picking up the calls to the AXD as they were being registered before RouteConfig.RegisterRoutes where the .axd exception is by default.