Could not load type System.ServiceModel.Activation.HttpModule

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′.

Solution:

To resolve this issue, run the following from command line:

aspnet_regiis.exe /iru

The aspnet_regiis.exe file can be found in either

• %windir%\Microsoft.NET\Framework\v4.0.30319
• %windir%\Microsoft.NET\Framework64\v4.0.30319 (on a 64-bit machine)