MVC4 Could not load type 'System.ServiceModel.Activation.HttpModule'

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

Have you started working on a .NET 4.0 project and received the following error?

Could not load type ‘System.ServiceModel.Activation.HttpModule’ from assembly ‘System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.Exception Details: System.TypeLoadException: Could not load type ‘System.ServiceModel.Activation.HttpModule’ from assembly ‘System.ServiceModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.

If you have, you probably have installed .Net framework 4.0 on IIS and then enable either a .Net 3.0 or 3.5 WCF feature.  To fix you need to reconfigure ASP.NET by using the following command depending on the version of ASP.NET you have installed.

IIS 32 bit

%SYSTEMROOT%\Microsoft.NET\Framework\v4.0.30319\aspnet_regiis /iru

IIS 64 bit

%SYSTEMROOT%\Microsoft.NET\Framework64\v4.0.30319\aspnet_regiis /iru

출처: http://www.jasonlinham.co.uk/2011/11/could-not-load-type-systemservicemodela.html