Symptom:

Users accessing WebUI receive 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'

Cause:

Problem with ASP.NET 4.0 installation.

Resolution:

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

aspnet_regiis.exe /iru

Aspnet_regiis.exe executable can be found in either:

• %windir%\Microsoft.NET\Framework\v4.0.30319

or

• %windir%\Microsoft.NET\Framework64\v4.0.30319 (64-bit OS)