Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel

Try with

c:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis.exe -iru

When multiple versions of the .NET Framework are executing side-by-side on a single computer, the ASP.NET ISAPI version mapped to an ASP.NET application determines which version of the common language runtime (CLR) is used for the application.

Above command will Installs the version of ASP.NET that is associated with Aspnet_regiis.exe and only registers ASP.NET in IIS.

https://support.microsoft.com/en-us/help/2015129/error-message-after-you-install-the--net-framework-4-0-could-not-load

I have Windows 8 installed on my machine, and the aspnet_regiis.exe tool did not worked for me either.

The solution that worked for me is posted on this link, on the answer by Neha: System.ServiceModel.Activation.HttpModule error

Everywhere the problem to this solution was mentioned as re-registering aspNet by using aspnet_regiis.exe. But this did not work for me.

Though this is a valid solution (as explained beautifully here)

but it did not work with Windows 8.

For Windows 8 you need to Windows features and enable everything under ".Net Framework 3.5" and ".Net Framework 4.5 Advanced Services".

Thanks Neha

Hello Thanks for the question; To resolve: "Could not load type 'System.ServiceModel.Activation.HttpModule' from assembly 'System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'"

In Windows Features check all for .NET 4 Advanced Services & .NET 3.5

Just like Nicolas Gago I tried aspnet_regiis.exe -iru but it didn't work. After the features were on then it yellow screen error was gone. Thanks;

You can install these features on windows server 2012 with powershell using the following commands:

Install-WindowsFeature -Name  NET-Framework-Features -IncludeAllSubFeature
Install-WindowsFeature -Name  NET-WCF-HTTP-Activation45 -IncludeAllSubFeature

You can get a list of features with the following command:

Get-WindowsFeature | Format-Table

Ok, finally got it.

Change this line in %windir%\System32\inetsrv\Config\ApplicationHost.config

<add name="ServiceModel" type="System.ServiceModel.Activation.HttpModule, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler" />

To

<add name="ServiceModel" type="System.ServiceModel.Activation.HttpModule, System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" preCondition="managedHandler,runtimeVersionv2.0" />

If this is not enough

Add this following line to the Web.config

<system.webServer>
  <modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>