IIS7 deployment - duplicate 'system.web.extensions/scripting/scriptResourceHandler' section

On attempting to deploy a .net 3.5 website on the default app pool in IIS7 having the framework section set to 4.0, I get the following error.

There is a duplicate 'system.web.extensions/scripting/scriptResourceHandler' section defined.

Commenting off the offending lines didn't help either. Any pointers on what I need to do or look at?

Solution 1:

If your plan is to deploy to an IIS that has an Application Pool running in .net 4.0 you will need to cleanup the web.config that includes all the section Definitions that point to .net 3.5. The reason this fails is because these section definitions are already included in the root web.config in .NET 4.0 (see %windir%\microsoft.net\framework\v4.0.30319\config\machine.config) that include all the system.web.extensions declared already.

Another quick fix is to have the application pool set to 2.0 just as your development machine appears to have,.

Solution 2:

The solution for me was to change the .NET framework version in the Application Pools from v4.0 to v2.0 for the Default App Pool:

Solution 3:

If, like me, you need to target v4 but can only build with .net 3.5, follow the instruction here. Just replace in your web.config the whole content of the <configSections> with:

<configSections>
<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
  <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
    <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
    <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions,  Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
      <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>
      <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
      <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
      <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
    </sectionGroup>
  </sectionGroup>
</sectionGroup>

Solution 4:

Set the application pool to 2.0, I did it and worked.