asp.net mvc 3 - How to Prevent MVC 4 Child Application inheriting Parent Application (Umbraco MVC3) web.config

Question

I have Umbraco deployed on the server. Currently I am trying to deploy MVC 4 Application as a child application but somehow the child's viewsweb.config inherits the configSections and sectionGroup from Umbraco's web.config. This results in the following error

Section or group name 'system.web.webPages.razor' is already defined. Updates to this may only occur at the configuration level where it is defined.

Umbraco's sectionGroup

<sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
  <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
  <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
</sectionGroup>

Child Application (MVC4) sectionGroup

<sectionGroup name="system.web.webPages.razor" type="System.Web.WebPages.Razor.Configuration.RazorWebSectionGroup, System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
  <section name="host" type="System.Web.WebPages.Razor.Configuration.HostSection, System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
  <section name="pages" type="System.Web.WebPages.Razor.Configuration.RazorPagesSection, System.Web.WebPages.Razor, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" />
</sectionGroup>

How can I prevent this from happening?

Answer 1

I had the exact same issue. I resolved it by adding an assembly redirect for razor to my child application like this:

<runtime>
<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <dependentAssembly>
   <assemblyIdentity name="System.Web.WebPages.Razor" publicKeyToken="31BF3856AD364E35" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-2.0.0.0" newVersion="2.0.0.0" />
  </dependentAssembly>
 </assemblyBinding>
</runtime>