Report Viewer Web Control Version 10 Gives Error Despite Set Up Correctly

Question

Reports are deployed and working, verified in Report Manager.

My application is an MVC2 app with my report on its own aspx page. This page worked with version 8 of the report viewer control, but we moved to new servers, upgraded sql server, and are trying to update our website to match.

The servers are Windows Server 2008 with IIS 7.5.

I am testing in both chrome and IE 9.

Despite my best efforts, I still get this error:

Report Viewer Configuration Error

The Report Viewer Web Control HTTP Handler has not been registered in the application's web.config file. Add <add verb="*" path="Reserved.ReportViewerWebControl.axd" type = "Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> to the system.web/httpHandlers section of the web.config file, or add <add name="ReportViewerWebControlHandler" preCondition="integratedMode" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" /> to the system.webServer/handlers section for Internet Information Services 7 or later.

But, I've already done this. in fact, I even read this from MSDN:

To use IIS 7.0 in Integrated mode, you must remove the HTTP handler in system.web/httpHandlers. Otherwise, IIS will not run the application, but will display an error message instead.

Just to be safe, I tried a combo of neither while adding the handler into IIS directly, just the web server http handler in my config, just the http handler in my config, and both.

Let's start with my web.config

<configuration
  <system.web>
    <httpRuntime maxQueryStringLength="4096" />
    <compilation targetFramework="4.0">
      <assemblies>
        <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="System.Web.Mvc, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        <add assembly="Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
        <add assembly="Microsoft.ReportViewer.Common, Version=10.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />
      </assemblies>
        <buildProviders>
            <add extension=".rdlc" type="Microsoft.Reporting.RdlBuildProvider, Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
        </buildProviders>
    </compilation>
  </system.web>
  <system.webServer>
    <handlers>
        <add name="ReportViewerWebControlHandler"  preCondition="integratedMode" verb="*" path="Reserved.ReportViewerWebControl.axd" type="Microsoft.Reporting.WebForms.HttpHandler,  Microsoft.ReportViewer.WebForms, Version=10.0.0.0,  Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"  />
    </handlers>
  </system.webServer>
</configuration>

I have the assemblies, the build provider, and the handler. What else could be wrong?

Answer 1

I found a quick and dirty workaround - to your web config add this:

<location path="Reserved.ReportViewerWebControl.axd">
<system.web>
  <authorization>
    <allow users="*" />
  </authorization>
</system.web>

I saw in fiddler that for some reason when page requested Reserved.ReportViewerWebControl.axd instead of getting HTTP 200 response server would send 302 - moved to login.aspx?returnurl="Reserved.ReportViewerWebControl.axd. So allowing all users to the handler path solves the problem.