Web Application Problems (web.config errors) HTTP 500.19 with IIS7.5 and ASP.NET v2

Question

This is driving the whole team crazy. There must be some simple mis-configured part of IIS or our Web Server, but every time we try to run out ASP.NET Web Application on IIS 7.5 we get the following error...

Here's the error in full:

HTTP Error 500.19 - Internal Server Error

The requested page cannot be accessed because the related configuration  
data for the page is invalid.

`Detailed Error Information` 
Module              IIS Web Core
Notification        Unknown
Handler             Not yet determined
Error Code          0x8007000d
Config Error
Config File         \\?\E:\wwwroot\web.config
Requested URL       http://localhost:80/Default.aspx
Physical Path 
Logon Method        Not yet determined
Logon User          Not yet determined
Config Source
   -1: 
    0: 

The machine is running Windows Server 2008 R2. We're developing our Web Application using Visual Studio 2008.

According to Microsoft the code 8007000d means there's a syntax error in our web.config -- except the project builds and runs fine locally. Looking at the web.config in XML Notepad doesn't bring up any syntax errors, either. I'm assuming it must be some sort of poor configuration on my part...?

Does anyone know where I might find further information about the error? Nothing is showing in EventViewer, either :(

Not sure what else would be helpful to mention...

Assistance is greatly appreciated. Thanks!

UPDATES! - POSTED WEB.CONFIG BELOW

Ok, since I posted the original question above, I've tracked down the precise lines in the web.config that were causing the error.

Here are the lines (they appear between <System.webServer> tags)...

    <httpHandlers>
        <remove verb="*" path="*.asmx"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    </httpHandlers>

Note: If I delete the lines between the <httpHandlers> I STILL get the error. I literally have to delete <httpHandlers> (and the lines inbetween) to stop getting the above error.

Once I've done this I get a new 500.19 error, however. Thankfully, this time IIS actually tells me which bit of the web.config is causing a problem...

    <handlers>
        <remove name="WebServiceHandlerFactory-Integrated"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    </handlers>

Looking at these lines it's clear the problem has migrated further within the same <system.webServer> tag to the <handlers> tag.

The new error is also more explicit and specifically complains that it doesn't recognize the attribute "validate" (as seen on the third line above). Removing this attribute then makes it complain that the same line doesn't have the required "name" attribute. Adding this attribute then brings up ASP.NET error...

Could not load file or assembly 'System.web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56' or one of its dependencies. The system cannot find the file specified.

Obviously I think these new errors have just arisen from me deleting the <httpHandlers> tags in the first place -- they're obviously needed by the application -- so the question remains: Why would these tags kick up an error in IIS in the first place???

Do I need to install something to IIS to make it work with them?

Thanks again for any help.

WEB.CONFIG

Here's the troublesome bits of our web.Config... I hope this helps someone find our problem!

<system.Web>

<!-- stuff cut out -->

    <httpHandlers>
        <remove verb="*" path="*.asmx"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56" validate="false"/>
    </httpHandlers>
    <httpModules>
        <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    </httpModules>
</system.web>

<system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
        <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    </modules>
    <remove verb="*" path="*.asmx"/>
    <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    <handlers>
        <remove name="WebServiceHandlerFactory-Integrated"/>
        <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
        <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=f2cb5667dc123a56"/>
    </handlers>
</system.webServer>

Answer 1

I had these exact symptoms and my issue was similar to Peter's. Was setting up an existing project on a new server. My project referenced the IIS7 URL Rewriting module, but that hadn't been installed yet on the new server. Installing it fixed my issue.

You can use the Microsoft Web Platform Installer to install it. Execute it, select Products, in the left menu select Server and find URL Rewrite in the list and install it.

Or you can download it here.